Drawing a graph from a function

I have a complex mathematical C++ function. I want a translated and easy to read graph out of it. Is there any software which can analyze special mathematical functions and draw an easy to read graph? Assume it's an encryption algorithm code.

I have tried a lot of software like Understand, WizGraph, etc. Is there something I should search for to find this type of s开发者_JS百科oftware?

Print the (x, y) values on cout, one pair (or tuple) of values per line, separated by commas. Run the gen program from command interpreter, redirect to textfile data.csv.

Load the comma-separated values text file in Excel or other spreadsheet program. Select the relevant data. Graph it.