Prev: How use datcomimport
Next: How can plot signal by cwt?
From: andrea182 on 29 Nov 2009 19:04
open contains a matrix 99*1

i want to create a matrix call derivato where the element number 1 is the subtract of the first with the second element of the vector open ...the element number 2 is the subtract of the the second with the third element...ecc...

function deriva(open)
for prova=1:(length(open)-1)
derivato(prova,1)=open(prova,1)-open(prova+1,1);
end


but it produce me a mistake...where is the error???

thanks a lot
From: ImageAnalyst on 29 Nov 2009 19:10
Why not just use the built-in diff() function?
From: andrea182 on 29 Nov 2009 19:17
ImageAnalyst <imageanalyst(a)mailinator.com> wrote in message <2783dc73-f95d-419a-b024-9c6af9e60652(a)j14g2000yqm.googlegroups.com>...
> Why not just use the built-in diff() function?

how can i do???

please it is so seample but i can't found the mistake...maybe is wrong open(prova,1) and i should chang this i don't know...
From: ImageAnalyst on 29 Nov 2009 19:32
You mean like this:

% Generate vectors of sample data.
vector1 = randperm(10)
% Subtract element i from element (i+1).
diffVector1 = diff(vector1)

% Subtract element (i+1) from element i.
% Note it's the same except a minus sign was added.
% This is what Andrea wants.
diffVector2 = -diff(vector1)
From: ImageAnalyst on 29 Nov 2009 19:39
If you really want to do it your way, then do this:
(Basically get rid of the ",1" since you apparently have a 1D vecotr
not a 2D array, and add a return (output) argument. I also changed
the input arg name from open (a reserved keyword) to inputVector.

function test
clc;
close all;
clear all;
workspace;
% Generate vectors of sample data.
vector1 = randperm(10)
% Subtract element (i+1) from element i.
% This is what Andrea wants.
diffVector2 = deriva(vector1)

function derivato = deriva(inputVector)
for prova = 1 : (length(inputVector)-1)
derivato(inputVector) = inputVector(prova) - inputVector(prova
+1);
end
 |  Next  |  Last
Pages: 1 2 3
Prev: How use datcomimport
Next: How can plot signal by cwt?