Category Archives: javascript

Matrix inversion, row ops, program added

The row operation matrix inversion method is so neat and ingenious, and it has the same operations for all dimensions of matrix.

Here is a step by step approach, where firstly the dimension is chosen, then the first of the buttons is selected (Start). After which the buttons are selected in order. The states of the left and right matrices are displayed at each stage, and finally the identity matrix appears on the left, and the inverse of the original matrix appears on the right.

http://mathcomesalive.com/mathsite/matrix%20prog%203.html

matrix-inverse-screen-dump-0

The first display shows the original matrix on the left. Nothing has been done yet.

 

matrix-inverse-screen-dump

The second one is the 2 x 2 matrix inverted.

matrix-inverse-screen-dump-2

The third is the 4 x 4 matrix inverted.

The matrices can be altered with the file name for the application, “matrix prog 3.html”. using right click and “view page source”. You are then on your own, with javascript !!!!!!!!

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Filed under arithmetic, computer, discrete model, engineering, javascript, Uncategorized

Javascript, you’ve got to love it

In almost all computer languages a string is just a list of characters, like this sentence.

Strings in Javascript are fun!

The toString() method and the function String(..) both convert a number to a string.
With x = 12.3 and y=10000000

String(x)*2 gives 24.6
String(x)/String(y) gives 0.00000123
String((100 + 23).toString()-((-1)*String(x))) gives 135.3
(100 + 23).toString()+String(x) gives 12312.3

Work it out !!!!

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Filed under javascript, programming languages