what does the "nest" function do?

The "Numerical Analysis" textbook by Timothy Sauer has code that I am supposed to implement. The code is for a function called "sin1" that approximates the sine curve with a degree 3 polynomial. It think y is the polynomial. The function ends with a command:

y=s*nest(3,c,x1,b)

c,xy and b are all variables calculated earlier in the function. If "nest" is something Sauer defined in his textbook, I haven't found it yet. And I cannot find anything searching the Matlab documentation online that describes a "nest" function.

Can someone tell me what "nest" is? And if it is a Matlab function, please tell me why searching documentation for "nest" doesn't reveal it. Thanks.

Answer 1

[Walter Roberson]

It is from the introduction in the book. You can find the source at http://media.pearsoncmg.com/aw/aw_sauer_num_analysis_2/nest.m

[Jay Gourley]

Thanks for a quick and clear answer.