Difference Calculation between current value and a specified prior value

Hello,

I use the following to calculate percentage change:

B = (diff(VMA)./(VMA(1:end-1))*100;

What this does is (x1 - x2) / x2....

How can i make it where i pick the prior value, for example i want the rate of change but looking back 10 values...therefore:

B = (x1 - x10) / x10

Thanks!

Answer 1

[David Hill]

Not sure exactly what you are after, an example would be helpful.

B=(x(1:10)-x(10:19))./x(10:19);

[IDN]

Thanks for helping me out. I want this calculation be done for all my array.Example out put on original code:

VMA B

5.247743 0

5.7918 10.36745 = ((5.7918 - 5.247743)/5.247743)*100

6.1518 6.215684 = ((6.1518 - 5.7918)/5.7918)*100 and so on...

6.311829 2.601329

6.429629 1.866337

6.456114 0.411932

6.562157 1.642518

6.376371 -2.83117

6.187729 -2.95847

6.108229 -1.2848

6.107386 -0.0138

6.111971 0.075085

5.996186 -1.89441

5.778271 -3.63422

5.484386 -5.08605

5.324986 -2.90643

5.232614 -1.73468

5.097386 -2.58434

5.072029 -0.49745

5.118757 0.921299

5.323328 3.996504

what i would like its something like B = ((5.323328 - 5.232614)/5.232614)*100 = 1.73363 be able to change how many values back i want the difference and percentage change changed.