How to plot a timeseries from excel table

Hi there,

I want to plot a time series of a two column table from excel. The date format is 'mm-yyyy'. I keep getting an invalid plot argument error. I have attached the table I am trying to plot below.

Thank you

Answer 1

[Amit Dhakite]

Hello Elliot,

Based on your description, it seems that you are trying to plot a timeseries from an Excel table, but are encountering an error due to the "mm_yyyy" column being of type "cell". Since a cell type is not a valid input for the plot function, we need to convert it to a proper timeseries type.

To resolve this issue, we can use the readtable function to read the data from the Excel sheet, and then convert the "mm_yyyy" column to a "timeseries" type using the datetime function with the appropriate input format. Once this is done, we can plot the data using the plot function.

Here is the updated code to perform the conversion and plotting:

% Reading the data from excel sheet
data = readtable('SGIdata.xlsx');

% Converting the "mm_yyyy" column from a "cell" type to a "timeseries" type
data.mm_yyyy = datetime(data.mm_yyyy, 'InputFormat', 'mm-yyyy');

% Plotting the data
plot(data.mm_yyyy, data.SGI);

To know more about the functions used above, kindly refer to the following links:

1. readtable(): https://www.mathworks.com/help/matlab/ref/readtable.html
2. datetime(): https://www.mathworks.com/help/matlab/ref/datetime.html
3. plot(): https://www.mathworks.com/help/matlab/ref/plot.html