How can I falsely increase the frequency of acquisition of a signal?

Hello,

I have to confront a 50 Hz (20 ms of period) pressure signal with a 5 Hz temperature signal (200 ms of period) to calculate the density. I would like to create 10 repeats of one temperature value. I was thinking to use a for cycle but I don't know how. Can anyone give me some suggestions? Thank you!

Answer 1

[Star Strider]

I do not clearly understand what you want to do.

However, if you want both signals to have the same sampling frequency, use the resample function on one of them (preferably the one with the higher sampling frequency to resample it to a lower sampling frequency).

If you want to repeat one of the signals, use the repmat function.

[Guglielmo Giambartolomei]

Hi Star Strider,

I would like to replicate one value for ten times. This for each row. I have an array called TE1607 with values acquired every 200 ms. Since I have to confront this array with another that contains values acquired every 20 ms, I have to replicate one value for ten times.

T_temp_2021_04_01_2 = readtable('2021_04_01_16_15_05_200ms.CSV','FileType','text','Delimiter', ';', 'DecimalSeparator', ',');

TE1607 = table2array(T_temp_2021_04_01_2(:,[1,57]));    %estraggo la prima e la 57esima colonna

length_TE1607 = length(TE1607);

TE1607new = zeros(length_TE1607*10,2);

TE1607new(1,:) = [TE1607(1,1) TE1607(1,2)];

for i = 2:length_TE1607
    TE1607new(i,:) = TE1607new(i-1,:);      %????
    
end

I will take a look at the fuctions you suggested.

Thank you,

Guglielmo

[Star Strider]

To repeat one value 10 times, one approach would be:

repeat1 = ones(1,10) * 42                               % Vector

repeat1 = 1×10

42 42 42 42 42 42 42 42 42 42

repeat2 = ones(5,10) * 42                               % Matrix

repeat2 = 5×10

42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42 42

Another approach is to use the repelem function.

Choose whatever works best for your application.

.

[Guglielmo Giambartolomei]

Dear Star Strider,

I used the repelem function and it works!

I thank you very much!

Guglielmo

[Star Strider]

As always, my pleasure!