I keep getting this error whilst predicting RUL

Hi so i am running matlabs RUL prediction code i keep on ketting this error what should i do i am so lost i want to do this RUL estimation from my undergraduate project heres the error.

'Unable to perform assignment because value of type 'duration' is not convertible to 'double'.

Caused by:

Error using duration/double (line 1075)

Undefined function 'double' for input arguments of type 'duration'. To convert from durations to numeric, use the SECONDS, MINUTES, HOURS, DAYS, or YEARS functions.'

this is the part of the code thats giving the error

numValidation = length(validationDataFused);

numBreakpoint = length(breakpoint);

error = zeros(numValidation, numBreakpoint);

for dataIdx = 1:numValidation

tmpData = validationDataFused{dataIdx};

for bpidx = 1:numBreakpoint

tmpDataTest = tmpData(1:ceil(end*breakpoint(bpidx)), :);

trueRUL = length(tmpData) - length(tmpDataTest);

[estRUL, ~, ~] = predictRUL(mdl, tmpDataTest);

error(dataIdx, bpidx) = estRUL - trueRUL;

end

end

[Siddharth Bhutiya]

The error message indicates that you are assigning a duration value to a double array somewhere in your code. If the error is coming from the code snippet you pasted above then it must be the following line.

error(dataIdx, bpidx) = estRUL - trueRUL;

here it seems that error might be a double array and the answer of (estRUL - trueRUL) is a duration?

[zuheir Jaffrali]

so in my code snippet estRUL is a duration and trueRUL isnt how do i change that i have tried everything if you can help please thanks

Answer 1

[Rishi]

Hi Zuheir,

I understand you want to know why you are getting this error. The following line is giving this error:

error(dataIdx, bpidx) = estRUL - trueRUL; 

This is because you are trying to assign ‘estRUL – trueRUL’, which is of type duration to ‘error’, an array of type double. To fix this, you can convert ‘estRUL -trueRUL’ to numeric type first, using ‘seconds()’, ‘minutes()’, ‘hours()’, based on how you want the conversion.

For example,

d = duration(1, 2, 3) 

d = duration
   01:02:03

s = seconds(d)

s = 3723

h = hours(d)

h = 1.0342

You can refer to the following documentation for further information:

https://www.mathworks.com/help/matlab/ref/duration.hours.html

Regards,

Rishi Shrimal