Formula Calculator for iPhone

Index > Information on functions

Formula calculator contains a number of advanced numerical evaluation functions. It is important to understand how these functions work, since the results they return may not be accurate. This applies in particular to numerical differentiation.

The functions below perform operations on other functions. One example is numerical integration. If the function func(a,b,c) is to be integrated with respect to parameter b it would be written as integrate(func(a,b,c),b,min,max) where parameters a and c could be numbers or parameters with valid values.

However, it is important that there be no arithmetic expressions in the argument list. For example integrate(func(2*a,b,c)-1,b,min,max) can cause an error, either due to the multiplication appearing in the argument list or the subtraction. If you need to subtract values from your function, just define another one: newFunc(a,b,c)=func(2*a,b,c)-1 and use the new function in the integration. This applies to all functions of functions, as described below.

There are technical notes on the following functions in this help manual:


Root finder - the solve( ) function

Numerical integration

Numerical differentiation

Fourier transform

Fitting functions to arrays of data

Matrix calculations