Plotting dates on x-axis

Hello! I have a 339x1 cell with dates in the format (ex. : 2015-05-01, 2015-05-04), and a 339x1 double with corresponding numbers. I'm trying to figure out how to plot the data with the dates on the x axis and numbers on the Y, but it gives me an error trying to plot data from a cell. I tried using cell2mat, but that just gives me a 339x10 char which also can't be plotted. Pretty new to Matlab, would really appreciate any help!

Answer 1

[Star Strider]

You need to convert the date strings to date numbers with the datenum function, plot them as date numbers, then use the datetick function to plot them as formatted dates and times.

[Ben Griffiths]

Thank you! How do I get the data out of a cell though and into a string so I can use it as the X axis?

[Star Strider]

My pleasure!

If it’s an array of strings such as '2015-05-01' (call it ‘datecell’ here), use datenum as:

dn = datenum(datecell, 'yyyy-mm-dd');

which should work.

Then as an example for the plot:

figure(1)
plot(dn, y)
datetick('x', 'yyyy-mm-dd')

or whatever format you want the dates in.

[Ben Griffiths]

ahhhh amazing! it worked! thank you so much!

[Star Strider]

My pleasure!

[Alex Backer]

What a beautiful function, thanks!

[Star Strider]

My pleasure!

[devi r nair]

i have 15937 data points starting from 16-05-1975 till 31-12-2018. the data points are numbered from 0-15637. i used this code for ploting date from 16-05-1975 till 31-12-2018 but shows wrong x axis values.

start = datenum(1975,05,16);

fin=datenum(2018,12,31);

datetick('x', 'yy mmm dd', 'keepticks')

pls help what is wrong here,

Answer 2

[Peter Perkins]

An alternative to Star Strider's suggestion, if you are using MATLAB R2014b or later, would be

plot(datetime(datecell),y)

That's it.