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Formula Calculator for iPhone

Index > Charts and graphs

The Formula calculator chart is designed to automatically display your graph data quickly. However, you can change most of these settings by selecting the Chart edit icon. This provides the main interface for graph types (linear, logarithmic or polar charts), the graph line types (solid or dashed), the line colours and for displaying the data points.

To create a graph you need to pass to Formula calculator a set of x-y pairs. Use the range function to create an array of x values, such as x=range(0,10,0.1) or x=[0,10,0.1]. This creates an array of numbers starting from 0 and finishing at 10, in increments of 0.1, which are stored with parameter name x. You then use this parameter (x) in a function or arithmetic expression. The result will also be an array. For example, y=x*x-3 returns in y an array of values, each corresponding to one of the x values. To plot y against x, simply include plot(x,y) in the input text field. When the calculator is run, it plots the graph. You can include multiple arrays in the plot statement, such as plot(x,2*x^2,3*x^3) which creates two graphs on the one chart window.

Information on how to format your graphs or read information from them are given in the links below.

Displaying data and formatting graphs

Chart properties - choosing graph types and labels

Formatting charts

Graph properties - line colours, line types and data points

The data cursor and zoom function