def _sparse(self, x, y, sparse):
tmpX=[]<EOL>tmpY=[]<EOL>for i in range(len(x)):<EOL><INDENT>if sparse == <NUM_LIT:1>:<EOL><INDENT>return x,y<EOL><DEDENT>if (i%sparse)==<NUM_LIT:0>:<EOL><INDENT>tmpX.append(x[i])<EOL>tmpY.append(y[i])<EOL><DEDENT><DEDENT>return tmpX, tmpY<EOL>
Method that removes every non sparse th element.

For example:
if this argument was 5, This method would plot the 0th, 5th,
10th ... elements.

Parameters
----------
x : list
    list of x values, of length j.
y : list
    list of y values, of length j.
sparse : integer
    Argument that skips every so many data points.