Instructions

This web-app is an attempt to allow spreadsheet type calculations using simple algebraic formulas. A variable corresponds to a single column in a spreadsheet, and that column can be referred to by name in other calculations.

The graph allows you to look at covarying relationships between different variables. The data tables allow you to see the actual values, along with summary statistics such as the minimum, maximum, and sum of the data.

The types of data that can be generated are as follows:

• range: A range is a set of data that has a definite first and last value with equally spaced values. You specify the first and last values and the number of data points.
• dependent: A dependent variable is calculated as some formula based on one or more previously defined variables. You actually just type the formula using the names of other columns. The derivative of a formula can also be generated using D(formula).
• table: This is for data that is not automatically generated, but is simply typed directly in. You might use this to import one or more columns of raw data. The first row defines the names; all remaining rows provide the data, where the values are separated by white space.
• sequence: A sequence allows you to define a set of values using some type of recursive formula.
  • arithmetic sequence: A sequence with equally spaced values such that subsequent values are always found by adding some constant number to the previous value.
  • geometric sequence: A sequence with equally spaced values such that subsequent values are always found by multiplying some constant number to the previous value.
  • recursive sequence: A sequence formed by applying any arbitrary function (based on a formula you type) to the previous value to determine the subsequent value. Arithmetic sequences use the function f(x)=x+a. Geometric sequences use the function f(x)=a*x.
  • accumulation sequence: A sequence that combines the idea of recursion and dependence on other columns such that the subsequent value is always the previous value in the sequence plus some function of other variables. This also allows for relative indexing on those variables.