Data (Stata-Java API)

java.lang.Object
- com.stata.sfi.Data

public final class Data
extends Object

This class provides access to the current Stata dataset. All variable and observation numbering begins at 1 unless otherwise stated. All methods are not thread-safe unless otherwise stated.

Example:

This example shows how to handle a Stata varlist along with if and in to restrict observations. The example calculates summary statistics and displays a table similar to Stata's summarize command.


	public static int summarize(String args[]) {
		int parsedVariables = Data.getParsedVarCount();
		long obsStart = Data.getObsParsedIn1();
		long obsEnd = Data.getObsParsedIn2();

		if (parsedVariables <= 0) {
			SFIToolkit.errorln("varlist required");
			return 100;
		}

		// display the header
		SFIToolkit.displayln("\n" +   "    " +
				"Variable {c |}        Obs        Mean    Std. Dev.       Min        Max");
		SFIToolkit.displayln("{hline 13}{c +}{hline 57}");

		for (int i = 1; i <= parsedVariables; i++) {         
			double sum = 0;
			double max = Double.MIN_VALUE;
			double min = Double.MAX_VALUE;
			double mean = 0;
			double stddev = 0;
			long count = 0;

			// get the real variable index for the ith parsed variable
			int varIndex = Data.mapParsedVarIndex(i);

			if (!Data.isVarTypeStr(varIndex)) {

				// calculate mean
				for (long obs = obsStart; obs <= obsEnd; obs++) {
					if (! Data.isParsedIfTrue(obs)) {
						continue;
					}
					double value = Data.getNum(varIndex, obs);
					if (Data.isValueMissing(value)) {
						continue ;
					}
					max = Math.max(max, value);
					min = Math.min(min, value);
					sum += value;
					count++;
				}
				mean = sum / count;

				// calculate std. dev.
				double d2sum = 0;
				for (long obs = obsStart; obs <= obsEnd; obs++) {
					if (! Data.isParsedIfTrue(obs)) {
						continue;
					}
					double value = Data.getNum(varIndex, obs);
					if (Data.isValueMissing(value)) {
						continue ;
					}
					d2sum += Math.pow(value-mean,2);
				}
				stddev = Math.sqrt(d2sum/(count-1));
			}

			// write out the results 
			String out = String.format("%12s {c |}%11s", 
					Data.getVarName(varIndex),
					SFIToolkit.formatValue(count, "%11.0gc"));
			if (count>0) {
				out += String.format("   %9s   %9s  %9s  %9s", 
						SFIToolkit.formatValue(mean,  "%9.0g"), 
						SFIToolkit.formatValue(stddev,"%9.0g"),
						SFIToolkit.formatValue(min,   "%9.0g"),
						SFIToolkit.formatValue(max,   "%9.0g"));
			}
			SFIToolkit.displayln(out);
			SFIToolkit.pollnow(); 
			// outer loop; poll each time to update display
			// avoid polling too often; use pollstd() when possible
		}
		return 0;
	}

From Stata...

 
. sysuse auto, clear
(1978 Automobile Data)

. javacall Examples summarize rep if mpg > 22 in 12/50, jar(examples.jar)

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+----------------------------------------------------------
       rep78 |          8        3.25     1.38873          1          5


// compare with built-in summarize command
. summarize rep if mpg > 22 in 12/50

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
       rep78 |          8        3.25     1.38873          1          5

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`TYPE_BYTE`
`static int`	`TYPE_DOUBLE`
`static int`	`TYPE_FLOAT`
`static int`	`TYPE_INT`
`static int`	`TYPE_LONG`
`static int`	`TYPE_STR`
`static int`	`TYPE_STRL`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static int`	`addVarByte(String name)` Add a variable of type byte to the current Stata dataset.
`static int`	`addVarDouble(String name)` Add a variable of type double to the current Stata dataset.
`static int`	`addVarFloat(String name)` Add a variable of type float to the current Stata dataset.
`static int`	`addVarInt(String name)` Add a variable of type int to the current Stata dataset.
`static int`	`addVarLong(String name)` Add a variable of type long to the current Stata dataset.
`static int`	`addVarStr(String name, int length)` Add a variable of type str to the current Stata dataset.
`static int`	`addVarStrL(String name)` Add a variable of type strL to the current Stata dataset.
`static int`	`allocateStrL(StrLConnector sc, long size)` Allocate a strL so that a buffer can be stored using `writeBytes`; the contents of the strL will not be initialized.
`static int`	`allocateStrL(StrLConnector sc, long size, boolean binary)` Allocate a strL so that a buffer can be stored using `writeBytes`; the contents of the strL will not be initialized.
`static int`	`dropVar(int var)` Drop the variable at the specified variable index.
`static int`	`getBestType(double value)` Get the best numeric data type for the specified value.
`static String`	`getFormattedValue(int var, int obs, boolean bValueLabel)` Deprecated. This method cannot access observations beyond 2^31-1. Use `getFormattedValue(int, long, boolean)` instead.
`static String`	`getFormattedValue(int var, long obs, boolean bValueLabel)` Read a value from the current Stata dataset, applying its display format.
`static int`	`getMaxStrLength()` Get the maximum length of a Stata string variable of type str.
`static int`	`getMaxVars()` Get the maximum number of variables Stata currently allows.
`static double`	`getMissingValue()` Get a Stata missing value.
`static double`	`getNum(int var, int obs)` Deprecated. This method cannot access observations beyond 2^31-1. Use `getNum(int, long)` instead.
`static double`	`getNum(int var, long obs)` Read a numeric value from the current Stata dataset.
`static int`	`getObsCount()` Deprecated. This method cannot get counts beyond 2^31-1. Use `getObsTotal()` instead.
`static long`	`getObsParsedIn1()` Get the first in a range of observations if javacall was called with the in qualifier.
`static long`	`getObsParsedIn2()` Get the last in a range of observations if javacall was called with the in qualifier.
`static long`	`getObsTotal()` Get the number of observations in the current Stata dataset.
`static int`	`getParsedIn1()` Deprecated. This method cannot get observations beyond 2^31-1. Use `getObsParsedIn1()` instead.
`static int`	`getParsedIn2()` Deprecated. This method cannot get observations beyond 2^31-1. Use `getObsParsedIn2()` instead.
`static int`	`getParsedVarCount()` Get the number of variables specified when javacall was called.
`static Double`	`getRealOfString(String s)` Get the double representation of a `String` using Stata's real() function.
`static String`	`getStr(int var, int obs)` Deprecated. This method cannot access observations beyond 2^31-1. Use `getStr(int, long)` instead.
`static String`	`getStr(int var, long obs)` Read a string value from the current Stata dataset.
`static int`	`getStrVarWidth(int var)` Get the width of a variable of type str.
`static int`	`getType(int var)` Get the data type for the specified variable.
`static int`	`getVarCount()` Get the number of variables in the current Stata dataset.
`static String`	`getVarFormat(int var)` Get the format for a Stata variable.
`static int`	`getVarIndex(String varname)` Look up the variable index for the specified name in the current Stata dataset.
`static String`	`getVarLabel(int var)` Get the label for a Stata variable.
`static String`	`getVarName(int var)` Get the variable name at a given variable index.
`static boolean`	`isParsedIfTrue(int obs)` Deprecated. This method cannot access observations beyond 2^31-1. Use `isParsedIfTrue(long)` instead.
`static boolean`	`isParsedIfTrue(long obs)` Determine if an observation for the if expression qualifier used with javacall is true or false.
`static boolean`	`isValueMissing(double value)` Test if a value is a Stata missing.
`static boolean`	`isVarlistSpecified()` Determine if a varlist was specified with javacall.
`static boolean`	`isVarTypeStr(int var)` Test if a variable is of type str.
`static boolean`	`isVarTypeString(int var)` Test if a variable's type is string.
`static boolean`	`isVarTypeStrL(int var)` Test if a variable is of type strL.
`static String`	`makeVarName(String s, boolean retainCase)` Attempt to form a valid variable name from a string.
`static int`	`mapParsedVarIndex(int var)` Map the variable index from the parsed varlist.
`static int`	`readBytes(StrLConnector sc, byte[] b)` Read a sequence of bytes from a strL in the current Stata dataset.
`static int`	`readBytes(StrLConnector sc, byte[] b, int off, int len)` Read a sequence of bytes from a strL in the current Stata dataset.
`static int`	`renameVar(int var, String newname)` Rename a Stata variable.
`static int`	`setObsCount(int obs)` Deprecated. This method cannot set observations beyond 2^31-1. Use `setObsTotal(long)` instead.
`static int`	`setObsTotal(long obs)` Set the number of observations in the current Stata dataset.
`static int`	`setVarFormat(int var, String format)` Set the format for a Stata variable.
`static int`	`setVarLabel(int var, String label)` Set the label for a Stata variable.
`static int`	`storeBytes(StrLConnector sc, byte[] bytes, boolean binary)` Store a byte buffer to a strL in the current Stata dataset.
`static int`	`storeNum(int var, int obs, double value)` Deprecated. This method cannot access observations beyond 2^31-1. Use `storeNum(int, long, double)` instead.
`static int`	`storeNum(int var, long obs, double value)` Store a numeric value in the current Stata dataset.
`static int`	`storeStr(int var, int obs, String value)` Deprecated. This method cannot access observations beyond 2^31-1. Use `storeStr(int, long, String)` instead.
`static int`	`storeStr(int var, long obs, String value)` Store a string value in the current Stata dataset.
`static int`	`writeBytes(StrLConnector sc, byte[] b)` Write a byte buffer to a strL in the current Stata dataset; the strL must be allocated using `allocateStrL` before calling this method.
`static int`	`writeBytes(StrLConnector sc, byte[] b, int off, int len)` Write `len` bytes from the specified byte buffer starting at offset `off` to a strL in the current Stata dataset; the strL must be allocated using `allocateStrL` before calling this method.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - TYPE_BYTE
```
public static final int TYPE_BYTE
```
    See Also:
    
    Constant Field Values
  - TYPE_INT
```
public static final int TYPE_INT
```
    See Also:
    
    Constant Field Values
  - TYPE_LONG
```
public static final int TYPE_LONG
```
    See Also:
    
    Constant Field Values
  - TYPE_FLOAT
```
public static final int TYPE_FLOAT
```
    See Also:
    
    Constant Field Values
  - TYPE_DOUBLE
```
public static final int TYPE_DOUBLE
```
    See Also:
    
    Constant Field Values
  - TYPE_STR
```
public static final int TYPE_STR
```
    See Also:
    
    Constant Field Values
  - TYPE_STRL
```
public static final int TYPE_STRL
```
    See Also:
    
    Constant Field Values
- Method Detail
  - getNum
```
public static double getNum(int var,
                            long obs)
```
    Read a numeric value from the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    Returns:
    
    The value.
  - getNum
```
@Deprecated
public static double getNum(int var,
                                         int obs)
```
    Deprecated. This method cannot access observations beyond 2^31-1. Use getNum(int, long) instead.
    
    Read a numeric value from the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    Returns:
    
    The value.
  - getStr
```
public static String getStr(int var,
                            long obs)
```
    Read a string value from the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    Returns:
    
    The String. Returns null if an error occurs.
  - getStr
```
@Deprecated
public static String getStr(int var,
                                         int obs)
```
    Deprecated. This method cannot access observations beyond 2^31-1. Use getStr(int, long) instead.
    
    Read a string value from the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    Returns:
    
    The String. Returns null if an error occurs.
  - getFormattedValue
```
public static String getFormattedValue(int var,
                                       long obs,
                                       boolean bValueLabel)
```
    Read a value from the current Stata dataset, applying its display format.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    bValueLabel - Use the value label when available.
    
    Returns:
    
    The formatted value as a String.
  - getFormattedValue
```
@Deprecated
public static String getFormattedValue(int var,
                                                    int obs,
                                                    boolean bValueLabel)
```
    Deprecated. This method cannot access observations beyond 2^31-1. Use getFormattedValue(int, long, boolean) instead.
    
    Read a value from the current Stata dataset, applying its display format.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    bValueLabel - Use the value label when available.
    
    Returns:
    
    The formatted value as a String.
  - storeNum
```
public static int storeNum(int var,
                           long obs,
                           double value)
```
    Store a numeric value in the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    value - Value to store.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - storeNum
```
@Deprecated
public static int storeNum(int var,
                                        int obs,
                                        double value)
```
    Deprecated. This method cannot access observations beyond 2^31-1. Use storeNum(int, long, double) instead.
    
    Store a numeric value in the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    value - Value to store.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - storeStr
```
public static int storeStr(int var,
                           long obs,
                           String value)
```
    Store a string value in the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    value - Value to store.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - storeStr
```
@Deprecated
public static int storeStr(int var,
                                        int obs,
                                        String value)
```
    Deprecated. This method cannot access observations beyond 2^31-1. Use storeStr(int, long, String) instead.
    
    Store a string value in the current Stata dataset.
    
    Parameters:
    
    var - Variable to access.
    
    obs - Observation to access.
    
    value - Value to store.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - getVarCount
```
public static int getVarCount()
```
    Get the number of variables in the current Stata dataset.
    
    Returns:
    
    The number of variables.
  - getObsTotal
```
public static long getObsTotal()
```
    Get the number of observations in the current Stata dataset.
    
    Returns:
    
    The number of observations.
  - getObsCount
```
@Deprecated
public static int getObsCount()
```
    Deprecated. This method cannot get counts beyond 2^31-1. Use getObsTotal() instead.
    
    Get the number of observations in the current Stata dataset.
    
    Returns:
    
    The number of observations.
  - setObsTotal
```
public static int setObsTotal(long obs)
```
    Set the number of observations in the current Stata dataset.
    
    Parameters:
    
    obs - The number of observations to set.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - setObsCount
```
@Deprecated
public static int setObsCount(int obs)
```
    Deprecated. This method cannot set observations beyond 2^31-1. Use setObsTotal(long) instead.
    
    Set the number of observations in the current Stata dataset.
    
    Parameters:
    
    obs - The number of observations to set.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - getType
```
public static int getType(int var)
```
    Get the data type for the specified variable.
    
    Parameters:
    
    var - Variable to access.
    
    Returns:
    
    The value representing the data type; may be TYPE_BYTE, TYPE_INT, TYPE_LONG, TYPE_FLOAT, TYPE_DOUBLE, TYPE_STR, or TYPE_STRL.
  - getBestType
```
public static int getBestType(double value)
```
    Get the best numeric data type for the specified value.
    
    Parameters:
    
    value - The value to test.
    
    Returns:
    
    The field value representing the data type; may be TYPE_BYTE, TYPE_INT, TYPE_LONG, TYPE_FLOAT, or TYPE_DOUBLE.
  - addVarDouble
```
public static int addVarDouble(String name)
```
    Add a variable of type double to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - addVarFloat
```
public static int addVarFloat(String name)
```
    Add a variable of type float to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - addVarLong
```
public static int addVarLong(String name)
```
    Add a variable of type long to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - addVarInt
```
public static int addVarInt(String name)
```
    Add a variable of type int to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - addVarByte
```
public static int addVarByte(String name)
```
    Add a variable of type byte to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - addVarStr
```
public static int addVarStr(String name,
                            int length)
```
    Add a variable of type str to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    length - Initial size of the variable. If the length is greater than getMaxStrLength(), then a variable of type strL will be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - addVarStrL
```
public static int addVarStrL(String name)
```
    Add a variable of type strL to the current Stata dataset.
    
    Parameters:
    
    name - Name of the variable to be created.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - getVarIndex
```
public static int getVarIndex(String varname)
```
    Look up the variable index for the specified name in the current Stata dataset.
    
    Parameters:
    
    varname - Name of the variable.
    
    Returns:
    
    The variable index. If the variable does not exist, 0 is returned.
    
    Note: When Stata version control is less than 15.0 and the variable does not exist, the number of variables plus one will be returned.
  - getVarName
```
public static String getVarName(int var)
```
    Get the variable name at a given variable index.
    
    Parameters:
    
    var - Index of the variable to look up.
    
    Returns:
    
    The name of the Stata variable.
  - renameVar
```
public static int renameVar(int var,
                            String newname)
```
    Rename a Stata variable.
    
    Parameters:
    
    var - Index of the variable to rename.
    
    newname - New variable name.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - getVarLabel
```
public static String getVarLabel(int var)
```
    Get the label for a Stata variable.
    
    Parameters:
    
    var - Index of the variable to look up.
    
    Returns:
    
    The variable's label.
  - setVarLabel
```
public static int setVarLabel(int var,
                              String label)
```
    Set the label for a Stata variable.
    
    Parameters:
    
    var - Index of the variable to label.
    
    label - New label.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - getVarFormat
```
public static String getVarFormat(int var)
```
    Get the format for a Stata variable.
    
    Parameters:
    
    var - Index of the variable to look up.
    
    Returns:
    
    The variable's format.
  - setVarFormat
```
public static int setVarFormat(int var,
                               String format)
```
    Set the format for a Stata variable.
    
    Parameters:
    
    var - Index of the variable to format.
    
    format - New format.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - dropVar
```
public static int dropVar(int var)
```
    Drop the variable at the specified variable index.
    
    Parameters:
    
    var - Variable to drop.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - makeVarName
```
public static String makeVarName(String s,
                                 boolean retainCase)
```
    Attempt to form a valid variable name from a string.
    
    Parameters:
    
    s - Source string.
    
    retainCase - If set, the case will not be converted to lowercase.
    
    Returns:
    
    The new variable name. Returns null if a valid name was not created.
  - getMaxStrLength
```
public static int getMaxStrLength()
```
    Get the maximum length of a Stata string variable of type str.
    
    Returns:
    
    The maximum length.
  - getMaxVars
```
public static int getMaxVars()
```
    Get the maximum number of variables Stata currently allows.
    
    Returns:
    
    The maximum number of variables.
  - isVarTypeString
```
public static boolean isVarTypeString(int var)
```
    Test if a variable's type is string.
    
    Parameters:
    
    var - The index of the variable to test.
    
    Returns:
    
    True if the variable is a string variable of either type str or type strL.
  - isVarTypeStr
```
public static boolean isVarTypeStr(int var)
```
    Test if a variable is of type str.
    
    Parameters:
    
    var - The index of the variable to test.
    
    Returns:
    
    True if the variable is of type str.
  - isVarTypeStrL
```
public static boolean isVarTypeStrL(int var)
```
    Test if a variable is of type strL.
    
    Parameters:
    
    var - The index of the variable to test.
    
    Returns:
    
    True if the variable is of type strL.
  - getStrVarWidth
```
public static int getStrVarWidth(int var)
```
    Get the width of a variable of type str.
    
    Parameters:
    
    var - The index of the variable to test.
    
    Returns:
    
    The width if the variable is of type str.
  - isValueMissing
```
public static boolean isValueMissing(double value)
```
    Test if a value is a Stata missing.
    
    Parameters:
    
    value - The value to test.
    
    Returns:
    
    True if the value is a Stata missing.
  - getMissingValue
```
public static double getMissingValue()
```
    Get a Stata missing value.
    
    Returns:
    
    The value of a Stata missing.
  - getRealOfString
```
public static Double getRealOfString(String s)
```
    Get the double representation of a String using Stata's real() function.
    
    Parameters:
    
    s - The string to convert.
    
    Returns:
    
    The numeric value. Returns null if an error occurs.
  - getObsParsedIn1
```
public static long getObsParsedIn1()
```
    Get the first in a range of observations if javacall was called with the in qualifier. If in was not specified, then the range will reflect the entire dataset.
    
    Returns:
    
    The first observation's number.
  - getParsedIn1
```
@Deprecated
public static int getParsedIn1()
```
    Deprecated. This method cannot get observations beyond 2^31-1. Use getObsParsedIn1() instead.
    
    Get the first in a range of observations if javacall was called with the in qualifier. If in was not specified, then the range will reflect the entire dataset.
    
    Returns:
    
    The first observation's number.
  - getObsParsedIn2
```
public static long getObsParsedIn2()
```
    Get the last in a range of observations if javacall was called with the in qualifier. If in was not specified, then the range will reflect the entire dataset.
    
    Returns:
    
    The last observation's number.
  - getParsedIn2
```
@Deprecated
public static int getParsedIn2()
```
    Deprecated. This method cannot get observations beyond 2^31-1. Use getObsParsedIn2() instead.
    
    Get the last in a range of observations if javacall was called with the in qualifier. If in was not specified, then the range will reflect the entire dataset.
    
    Returns:
    
    The last observation's number.
  - isVarlistSpecified
```
public static boolean isVarlistSpecified()
```
    Determine if a varlist was specified with javacall.
    
    Returns:
    
    True if javacall was passed a varlist.
  - getParsedVarCount
```
public static int getParsedVarCount()
```
    Get the number of variables specified when javacall was called. If a varlist was not specified, then all the variables are implied.
    
    Returns:
    
    The number of variables.
  - mapParsedVarIndex
```
public static int mapParsedVarIndex(int var)
```
    Map the variable index from the parsed varlist. For example, if javacall is called with three variables, loop over 1, 2, and 3. For each iteration, use this method to translate 1, 2, and 3 to the correct variable index within the dataset.
    
    Parameters:
    
    var - Parsed variable index.
    
    Returns:
    
    The actual variable index in the dataset.
  - isParsedIfTrue
```
public static boolean isParsedIfTrue(long obs)
```
    Determine if an observation for the if expression qualifier used with javacall is true or false.
    
    Parameters:
    
    obs - The observation to test.
    
    Returns:
    
    True when the if expression evaluates to true for the specified observation. When an if expression is not specified with javacall, this function will return true.
  - isParsedIfTrue
```
@Deprecated
public static boolean isParsedIfTrue(int obs)
```
    Deprecated. This method cannot access observations beyond 2^31-1. Use isParsedIfTrue(long) instead.
    
    Determine if an observation for the if expression qualifier used with javacall is true or false.
    
    Parameters:
    
    obs - The observation to test.
    
    Returns:
    
    True when the if expression evaluates to true for the specified observation. When an if expression is not specified with javacall, this function will return true.
  - readBytes
```
public static int readBytes(StrLConnector sc,
                            byte[] b,
                            int off,
                            int len)
                     throws IOException
```
    Read a sequence of bytes from a strL in the current Stata dataset.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    b - The buffer into which the data are read.
    
    off - The start offset in the destination array b.
    
    len - The maximum number of bytes read.
    
    Returns:
    
    The total number of bytes read into the buffer, or -1 if there are no more data because the end has been reached; may return a negative Stata return code if an error occurs.
    
    Throws:
    
    IOException - throws an IOException if an error occurs.
  - readBytes
```
public static int readBytes(StrLConnector sc,
                            byte[] b)
                     throws IOException
```
    Read a sequence of bytes from a strL in the current Stata dataset.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    b - The buffer into which the data are read.
    
    Returns:
    
    The total number of bytes read into the buffer, or -1 if there are no more data because the end has been reached; may return a negative Stata return code if an error occurs.
    
    Throws:
    
    IOException - throws an IOException if an error occurs.
  - storeBytes
```
public static int storeBytes(StrLConnector sc,
                             byte[] bytes,
                             boolean binary)
```
    Store a byte buffer to a strL in the current Stata dataset.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    bytes - Bytes to store.
    
    binary - Mark the data as binary.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - writeBytes
```
public static int writeBytes(StrLConnector sc,
                             byte[] b)
```
    Write a byte buffer to a strL in the current Stata dataset; the strL must be allocated using allocateStrL before calling this method. The buffer size may be smaller than the allocation size for the strL so that calling this method multiple times will write the data in chunks. The current position of each write will be automatically maintained. Writing beyond the allocation size is not permitted.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    b - The buffer holding the data to store.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - writeBytes
```
public static int writeBytes(StrLConnector sc,
                             byte[] b,
                             int off,
                             int len)
```
    Write len bytes from the specified byte buffer starting at offset off to a strL in the current Stata dataset; the strL must be allocated using allocateStrL before calling this method. The buffer size may be smaller than the allocation size for the strL so that calling this method multiple times will write the data in chunks. The current position of each write will be automatically maintained. Writing beyond the allocation size is not permitted.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    b - The buffer holding the data to store.
    
    off - The offset into the buffer.
    
    len - The number of bytes to write.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - allocateStrL
```
public static int allocateStrL(StrLConnector sc,
                               long size)
```
    Allocate a strL so that a buffer can be stored using writeBytes; the contents of the strL will not be initialized. By default, the data will be marked as binary.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    size - The size in bytes.
    
    Returns:
    
    Return code from Stata; 0 if successful.
  - allocateStrL
```
public static int allocateStrL(StrLConnector sc,
                               long size,
                               boolean binary)
```
    Allocate a strL so that a buffer can be stored using writeBytes; the contents of the strL will not be initialized.
    
    Parameters:
    
    sc - The StrLConnector representing a strL.
    
    size - The size in bytes.
    
    binary - Mark the data as binary. Note that if the data are not marked as binary, Stata expects that the data be UTF-8 encoded. An alternate approach is to call storeStr, where the encoding is automatically handled.
    
    Returns:
    
    Return code from Stata; 0 if successful.

Class Data

Example:

From Stata...

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TYPE_BYTE

TYPE_INT

TYPE_LONG

TYPE_FLOAT

TYPE_DOUBLE

TYPE_STR

TYPE_STRL

Method Detail

getNum

getNum

getStr

getStr

getFormattedValue

getFormattedValue

storeNum

storeNum

storeStr

storeStr

getVarCount

getObsTotal

getObsCount

setObsTotal

setObsCount

getType

getBestType

addVarDouble

addVarFloat

addVarLong

addVarInt

addVarByte

addVarStr

addVarStrL

getVarIndex

getVarName

renameVar

getVarLabel

setVarLabel

getVarFormat

setVarFormat

dropVar

makeVarName

getMaxStrLength

getMaxVars

isVarTypeString

isVarTypeStr

isVarTypeStrL

getStrVarWidth

isValueMissing

getMissingValue

getRealOfString

getObsParsedIn1

getParsedIn1

getObsParsedIn2

getParsedIn2

isVarlistSpecified

getParsedVarCount

mapParsedVarIndex

isParsedIfTrue

isParsedIfTrue

readBytes

readBytes

storeBytes

writeBytes

writeBytes

allocateStrL

allocateStrL