# Iso value in a plot
**URL:** https://community.freefem.org/t/iso-value-in-a-plot/1776
**Category:** General Discussion
**Created:** [May 25, 2022, 9:03am UTC](https://community.freefem.org/t/iso-value-in-a-plot/1776 "2022-05-25T09:03:41Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@fas41](https://community.freefem.org/u/fas41)
#### Post date: [May 25, 2022, 9:03am UTC](https://community.freefem.org/t/iso-value-in-a-plot/1776/1 "2022-05-25T09:03:41Z")
HI
Is there any way I can fix min and max of iso value in a freedom plot?
Actually I want the same number representing same color in two different codes so that I can compare based on colored area, so I thought if I fix the iso max and iso min, I will get that.
---
### Author:  [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [May 25, 2022, 5:17pm UTC](https://community.freefem.org/t/iso-value-in-a-plot/1776/2 "2022-05-25T17:17:29Z")
you can set the value of plot isovalue with
```auto
tutorial/NS-BackwardStep.edp:plot(psi,wait=0,viso=psiviso);
```
where the value of psiviso array is:
```auto
real[int] psiviso(31);
{int k=0;
for(int i=-20;i<0;i++)
psiviso[k++] = i*2./3.*(H-0.5)/20;
for(int i=0;i<=10;i++)
psiviso[k++] = i*2./3.*(H-0.5)/100/(H*H*H);
}
```
---
### Author:  [@fas41](https://community.freefem.org/u/fas41)
#### Post date: [June 2, 2022, 1:47am UTC](https://community.freefem.org/t/iso-value-in-a-plot/1776/3 "2022-06-02T01:47:07Z")
hi thanks, does it mean if I use this array in two different codes, the color palette will be same? I want same number represent same color in two different codes. I thought I can do it by fixingI minimum of iso value say 0.1 and max1.1 in every code so that it gives me same color range
---
### Author:  [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [June 2, 2022, 9:12am UTC](https://community.freefem.org/t/iso-value-in-a-plot/1776/4 "2022-06-02T09:12:03Z")
Here the same va is the same color , try !!!