MATLAB: Import date data from excel

Question

I have an excel sheet with two columns. The first column has the date in the format mmm-yy and the second column has the values.

Column A Column B Jan-05 Value Feb-05 Value Mar-05 Value

I imported the dates successfully as,

month_year=xlsread('Filename','A2:A133'); formatOut = 'mmm-yy'; month_year = datestr(month_year,formatOut)

The output month_year is of 'char' type of 132×6.

I wish to plot with x-axis being month_year and y-axis the corresponding values. So I write something like,

month_year=datenum(month_year,'mmm-yy') plot(month_year, data) datetick('x','mmmyyyy','keepticks','keeplimits')

However in the process all the dates in the x-axis are now 'Jan 00'

How do I solve this ?

Answer 1

Unless you are using an older version of MATLAB, you are likely much better of using readtable to read your data into a table, converting the date text into a datetime (if necessary, depends on what version of MATLAB you're using and how the spreadsheet is set up), and plotting the vales vs. the datetimes.

Let's assume readtable gives you a table something like this:

>> t = table({'Jan-05';'Feb-05';'Mar-05'},[1;2;3],'VariableNames',{'A' 'B'})
t =
  3×2 table
       A        B
    ________    _
    'Jan-05'    1
    'Feb-05'    2
    'Mar-05'    3

Do this:

>> t.A = datetime(t.A,'InputFormat','MMM-yy')
t =
  3×2 table
         A         B
    ___________    _
    01-Jan-2005    1
    01-Feb-2005    2
    01-Mar-2005    3
>> plot(t.A,t.B)

If you need to tinker with the x axis ticks or labels, here's where to find them:

>> h = gca;
>> h.XAxis
ans = 
  DatetimeRuler with properties:
               Limits: [01-Jan-2005    05-Mar-2005]
           TickValues: [01-Jan-2005    15-Jan-2005    29-Jan-2005    12-Feb-2005    26-Feb-2005]
      TickLabelFormat: 'MMM dd'
    Show all properties