# [SOLVED] Python function that plots functions

## Issue

I’m currently trying to define a function in python that plots functions.

``````def plota_f(x0, xf, n):
xpoints = []
ypoints = []
for i in range(0,n):
xpoints.append(x0+(xf-x0)/n *i)
ypoints.append(np.sin(x0+(xf-x0)/n *i))
plt.plot(xpoints, ypoints)
plt.show()
``````

that plots a Sin function from x0 to xf with n steps, but I would like to be able to add a parameter f

``````def plota_f(f,x0,xf,n):
``````

so that I could call like

``````plota_f(x**2,0,10,100)
``````

and plot a quadratic function or call

``````plota_f(np.sin(x),0,10,100)
``````

and plot a sin function. Is there a simple way of doing that?

Edit: this is the code I got after the answer

``````def plota_f(f,x0,xf,n):
xpoints = []
ypoints = []
for i in range(0,n):
xpoints.append(x0+(xf-x0)/n *i)
x=x0+(xf-x0)/n *i
ypoints.append(eval(f))
plt.plot(xpoints, ypoints)
plt.show()
``````

## Solution

It’s pretty easy with numpy:

from x0 to xf with n steps

This is the definition of `np.linspace`

be able to add a parameter f

Use a lambda function

Demo:

``````def plota_f(f, x0, xf, n):
# Use with caution, eval can be dangerous
xpoints = np.linspace(x0, xf, n, endpoint=True)
ypoints = eval(f)
plt.plot(xpoints, ypoints)
plt.show()

plota_f('x**2', 0, 10, 100)
`````` 