# Printing of new values using User-Defined Constitutive Model
**URL:** https://forum.itascainternational.com/t/printing-of-new-values-using-user-defined-constitutive-model/1427
**Category:** FLAC2D
**Created:** [April 26, 2024, 7:06am UTC](https://forum.itascainternational.com/t/printing-of-new-values-using-user-defined-constitutive-model/1427 "2024-04-26T07:06:48Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@SamVarun10](https://forum.itascainternational.com/u/SamVarun10)
#### Post date: [April 26, 2024, 7:06am UTC](https://forum.itascainternational.com/t/printing-of-new-values-using-user-defined-constitutive-model/1427/1 "2024-04-26T07:06:48Z")
Hello everyone,
I need to ask about cpp file of e.g. Strain Softening Model. Is there a way in which I can use things like std::cout etc. to print some values in FLAC?
Is there some way to do this for each step/zone?
For eg in this code snippet
if (iPlas != 0) {
s-\>viscous\_ = false; // inhibit viscous strains
s-\>stnS\_ = info.resolve(prin);// transform back to refrence frame
/\* — hadRdening padRameter accumulation — _/
if (iPlas==1) {
/_ — shear padRameter — _/
Double dDe1p = dFsurf \* sF1\_;
Double dDe3p = dFsurf \* sF3\_;
Double dDepa = d1d3 \* (dDe1p + dDe3p);
dDe1p -= dDepa;
dDe3p -= dDepa;
s-\>working\_[Dqs] += sqrt(0.5 \* (dDe1p_dDe1p+dDepa_dDepa+dDe3p_dDe3p)) \* s-\>getSubZoneVolume(); //(2.141)
How to print s-\>working\_[Dqs]
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### Author:  [@markus](https://forum.itascainternational.com/u/markus)
#### Post date: [April 29, 2024, 1:27pm UTC](https://forum.itascainternational.com/t/printing-of-new-values-using-user-defined-constitutive-model/1427/2 "2024-04-29T13:27:40Z")
As far as I know, there is no easy interface to write to the GUI from a DLL. A couple of years ago an Itascan gave us some pointers by which we were able to write to the GUI using the iprogram interface, but this was a nightmare to set up.
For debugging purposes I would therefore recommend to either do the “old school” writing to a log file or to step through the code using the Debugger linked to the FLAC application.