Error with reading excel file

start_date = datetime(2020,1,2,0,0,0);
end_date = datetime(2020,1,3,0,0,0);
demand = load_demand('Demand_timeseries_1hourResolution.xlsx',start_date,end_date);             
figure (21)
plot(demand.Time, demand.Values)                                                                
xlabel('Time');                                                                                 
ylabel('Demand [MW]');                                                                          
title('Demand')

I'm having bit of a frustrating issue with my scrript. I wantto read excel file in the same folder where I have my matlab file, however it keeps giving me the same error

'Unrecognized function or variable 'load_demand''

The script works for everybody else but me, so I can't find the problem.

I hope somebody can help me

[Walter Roberson]

load_demand does not appear to be a Mathworks function (unless it happens to be in one of the examples somewhere)

[Anders Vigen]

@Walter RobersonOkay so if it's not a Mathworks function (even though seems weird since it works on my colleagues computer), how would I fix this problem, I would obviously need to use a different function?

[Walter Roberson]

Have one of them query

which load_demand

and see what shows up.

[Anders Vigen]

@Walter Roberson unfortunately it says the same thing.

[Walter Roberson]

What was the output on both systems?

[Anders Vigen]

@Walter Roberson I'm not sure what you mean by output. But the purpose of the script was to plot the load demand for a specific day, from an excel sheet containing the load demand for very day for a year.

[Walter Roberson]

which load_demand

When you executed that command on your colleague's system what was the output?

[Anders Vigen]

I obtained the below plot.

[Walter Roberson]

If you obtained a plot when you gave that command, then you have accidentally overwritten the important MATLAB command "which".

>> which load_demand
'load_demand' not found.
>> which timerange
/Applications/MATLAB_R2020b.app/toolbox/matlab/datatypes/tabular/timerange.m  % timerange constructor

That's the sort of output you should have seen when you ran the command

which load_demand

on your colleague's computer: either "not found" or the location of the implementing method.

[Anders Vigen]

@Walter Roberson this might be a stupid question, but if I did accidentally overwrite the which command, how do I fix that?

[Walter Roberson]

What shows up if you give the command

builtin('which', 'which')

built-in (/MATLAB/toolbox/matlab/general/which)

[Anders Vigen]

It gives me

built-in (C:\Program Files\MATLAB\R2020b\toolbox\matlab\general\which)
'load_demand' not found.
Unrecognized function or variable 'load_demand'.

Error in main_2 (line 136)
demand = load_demand('Demand_timeseries_1hourResolution.xlsx',start_date,end_date);

And this was the script I put in

builtin('which', 'which')
which load_demand
demand = load_demand('Demand_timeseries_1hourResolution.xlsx',start_date,end_date); 

[Walter Roberson]

Okay, and what about on your colleague's computer? What shows up on there?

At this point, I can pretty much predict an implimentation of the function:

function demand = load_demand(filename, start_date, end_date)
   T = readtable(filename);
   mask = isbetween(T{:,1}, start_date, end_date);
   demand = T(mask,:);
end

Answer 1

[Anders Vigen]

https://se.mathworks.com/matlabcentral/answers/750099-plotting-timetable-in-matlab#comment_1344474

This solution works for this problem as well.

Answer 2

[Ani Singh]

From the error "'Unrecognized function or variable 'load_demand" looks like you do not have "load_demand" user-defined function implementation(which is not function provided by MathWorks).

Please get the "load_demand" file from your colleague's system or write implementation your function.

Example:

function demand = load_demand(fileName, startDate, endDate)
   excelOutput = readtable(fileName);
   query = isbetween(excelOutput{:,1}, startDate, endDate);
   demand = excelOutput(query,:);
end

[Walter Roberson]

According to other posts by the same user, the file turns out to have a date column and an hours column, but the hours problem had text such as '00-01' and '07-08'