Statistics
Jaap MurreDemo of built-in statistics functions
There are a number of built-in basic statistics functions, such as mean and variance. These take an array of numbers as argument and return a single Number value. To avoid confusion with other functions, they must always be prefixed with stat, as in stat.mean(arr), where arr is an array of Numbers.
- stat.mean()
- Average
stat.median()
- Median
stat.stddev()
- Standard deviation
stat.stderr()
- Standard error
stat.variance()
- Variance
stat.sumsqerr()
- Sum of squared errors (i.e., sume of squared deviations from mean)
stat.min()
- Lowest value
stat.max()
- Highest value
stat.range()
- Difference between highest and lowest value
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var arr = [2,1,4,6,1,3],
arr_m = stat.mean(arr),
arr_sd = stat.stddev(arr);
// Use toFixed(n) to convert a Number to text with n decimals
// Don't use it before further calculations as it returns a text string
text("Average: " + arr_m.toFixed(2));
await(2000);
text("Standard Dev: " + arr_sd.toFixed(2));
await(2000);
/*
The following functions take an array as an argument and return one value
stat.mean()
Average
stat.median()
Median
stat.stddev()
Standard deviation
stat.stderr()
Standard error
stat.variance()
Variance
stat.sumsqerr()
Sum of squared errors (i.e., sume of squared deviations from mean)
stat.min()
Lowest value
stat.max()
Highest value
stat.range()
Difference between highest and lowest value
*/
// Square root, sin, round, etc. are already in Javascript in the Math library
// E.g., see https://www.w3schools.com/js/js_math.asp
var x = Math.sqrt(100);
text("sqrt(100): " + x);
await(2000);