# Re: st: RE: Create graph directly from matrix?

 From Nick Winter <[email protected]> To [email protected] Subject Re: st: RE: Create graph directly from matrix? Date Mon, 16 Nov 2009 12:25:44 -0500

```Ah, interesting.

```
Looking within -_matplot-, it looks like the fundamental answer to my question might be "no", since that program creates temporary variables that it then plots.
```
```
But it uses an interesting construction that may help me go the variables route without using -svmat-:
```
gen x = Xy[_n,1] in 1/16

```
creates a new variable -x- from the first column of matrix Xy. Pretty spiffy to use _n to tag the observation number/row number.
```
- Nick

Nick Cox wrote:
```
Check out the undocumented command -_matplot-. Nick [email protected]
```Nick Winter

I'm wondering if there is a way to convert the values held into a matrix

```
into a graph (ie, into a serset that serves as the basis for a graph) directly, without first making the matrix into variables?
```
Why I'm curious:

```
I'm thinking about revising my -oprobpr- command, which plots predicted probabilities after order l/probit models. The new -margins- command can fairly easily calculate what's required for the plotting, and those results can be saved as a matrix, using -margins-'s -post- option.
```
So I'd like to plot the estimates returned in e(b) against values in
e(at).

I can put this stuff all together in one matrix, eg:

sysuse auto
probit foreign mpg price weight

margins, atmeans at(mpg=(12(2.9)41)) post
mat b = e(b)
mat X = e(at)
mat Xy = X , b'

```
Then I'd like to create, eg, a line plot of the final column (named y1) against the first column (mpg).
```
```
I can, of course, use -svmat-, graph the relevant variables, and drop the variables.
```
But I'd love a more elegant solution.

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```
```
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--------------------------------------------------------------
Nicholas Winter                                 434.924.6994 t
Assistant Professor                             434.924.3359 f
Department of Politics                  [email protected] e
University of Virginia          faculty.virginia.edu/nwinter w
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