How do I plot a table with dates?

Hi! I am trying to plot a table, this is a short snippet of it:

date CountryA CountryB CountryC

_____ _______ _______ _______

2020-01-01 {[ 17]} {[ 18]} {[ 12]}

2020-01-02 {[ 15]} {[ 13]} {[ 16]}

2020-01-03 {[ 20]} {[ 15]} {[ 16]}

I am attempting to do this by using this:

plot(T{:,1},T{:,2:4})

It gives me this error:

Error using plot

Invalid data argument.

What's wrong with it and how can I fix it?

Answer 1

[VBBV]

T = table({'2020-01-01';'2020-01-02';'2020-01-03'},[17;15;20],[18;13;15],[12;16;16],'VariableNames',{'Date','Country A','Country B','Country C'})
TT = table2cell(T)
T1 = datetime(TT(:,1)) 
plot(T1,cell2mat(TT(:,2:4)))
ax = gca; set(ax,'XTickLabels',{'1 Jan 2020', '','3 Jan 2020','', '5 Jan 2020'})

[Scarlet Stanton]

Thanks!

[Peter Perkins]

No, don't do that. There's no need to convert to and from a cell array.

Scarlett, you have (it appears) a table with one datetime variable and three variables that should be numeric but are in fact cell arrays. That's bad for several reasons, not the least of which is that you won't be able to do anything useful with the numeric data in cell arrays. You need to figure out why you are ending up with that table. One wild guess might be that you are using xlsread when you should be using readtable. In fact, what you want to have is a timetable.

One you remedy that, then what you have, plot(T{:,1},T{:,2:4}), will work. You may find this more readable:

plot(T.date,T.CountryA, T.date,T.CountryB, T.date,T.CountryC)

but your use of brace subscripting to extract the datetimes and the numbers is correct, but I'd suggest

plot(T.date,T{:,["CountryA" "CountryB" "CountryC"]})