# How to print values on gauss points

Following steps are necessary to be abale to print values on **Gauss points**:

1. Call **PrintOnGaussPoints** function of the **gid_io** with the variable that you want to see, i.e **CONTACT_STICK**, to
the *python* file

gid_io.PrintOnGaussPoints(CONTACT_STICK, self.model_part, time);

Note that the variable **must** be a double, a vector of doubles or a Matrix of doubles.

2. This function in his turn calls a function inside your **element** that is called **GetValueOnIntegrationPoints**.

This is an standard function of class of **element** and has 3 representatives for double, vector of doubles and Matrix of doubles.

One example of it can be found as ,

void PfemContactElement3D::GetValueOnIntegrationPoints(const Variable<double>& rVariable, std::vector<double>& rValues, const ProcessInfo& rCurrentProcessInfo) { if (rVariable == CONTACT_STICK){ for (unsigned int PointNumber = 0; PointNumber < 1; PointNumber++) { rValues[PointNumber] = double(this->GetValue(IS_CONTACT_MASTER));}}}

Here **rVariable** can be any registered variable of KRATOS. **rValues** is always a vector that has the length of the number of Gauss points in each element.
This vector is filled as is desired and then its values is printed in GID through the function **PrintOnGaussPoints**presented in step 1.