??? In an assignment A(I) = B, the number of elements in B and I must be the same.

I have to write a program for school that can read the temperture in a rooftile dryingroom. A NTC will be connected to a data-acquiring card. but when I want to use formulas on the whole matrix this creates is gives the before stated error. Below is the relevant code (the last 2 lines produce the error):

...
s=daq.createSession('ni');
s.addAnalogInputChannel('dev1',0,'Voltage');
s.Rate=rate;
s.DurationInSeconds=tijdseenheid;
[data,time]=s.startForeground;
...
const_a=input('The value of consistant A: ');
const_b=input('The value of consistant B: ');
weerstand=input('The value of the resistor: ');
ubron=input('The value of the powersupply: ');
data(:)=((ubron-data)*weerstand)/data;
data(:)=const_b/log((data)/const_a);
...

[Jan]

The error cannot be produced by two lines. Only one command can cause the error - afterwards Matlab stops.

Answer 1

[Tom]

I'm not entirely sure what the variables are, but you may be meaning to do an element-by-element divide, not a matrix divide: in this case use ./ not / to divide.

[Ruben Wulms]

We tried that but that also doesn't help.

We indeed try to put each element from the data matrix into the formula.

[Jan]

You definitely need the elementwise operators. If you've tried this already without success, post your trials here.