Using a cell array within datenum, convert to string with format before necessary?

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From reading in this Excel file into MATLAB:

[frates, fdlable] = xlsread('C:\Users\Nancy\Documents\Research\Data\USTreasury\USTreasuryDataset\FredTreasuryRatesMon','A8:X818')

I get a cell array rates fdlable1 811 by 12 of Excel dates, format m/d/yyyy that I want convert to serial date numbers through datenum.

Must I convert fdlable1 'm/d/yyyy' to a string variable first before using datenum?

Here the assignment fails because there are empty cells in fdlable1:

date_num = cellfun(@datenum, fdlable1, 'UniformOutput', false);

Warning: Usage of DATENUM with empty date character vectors or empty strings is not supported. Results may change in future versions.

fdlable1 =fdlable(:,1:2:23);

811 x 12 from 811 x 23
fdlable: '7/1/1954' '' '7/1/2001' '' '1/1/1934' '' '12/1/1958' '8/1/1954' '' '8/1/2001' '' '2/1/1934' '' '1/1/1959' '9/1/1954' '' '9/1/2001' '' '3/1/1934' '' '2/1/1959' '10/1/1954' '' '10/1/2001' '' '4/1/1934' '' '3/1/1959' '11/1/1954' '' '11/1/2001' '' '5/1/1934' '' '4/1/1959' '12/1/1954' '' '12/1/2001' '' '6/1/1934' '' '5/1/1959' '1/1/1955' '' '1/1/2002' '' '7/1/1934' '' '6/1/1959' '2/1/1955' '' '2/1/2002' '' '8/1/1934' '' '7/1/1959' '3/1/1955' '' '3/1/2002' '' '9/1/1934' '' '8/1/1959' '4/1/1955' '' '4/1/2002' '' '10/1/1934' '' '9/1/1959' '5/1/1955' '' '5/1/2002' '' '11/1/1934' '' '10/1/1959' '6/1/1955' '' '6/1/2002' '' '12/1/1934' '' '11/1/1959' '7/1/1955' '' '7/1/2002' '' '1/1/1935' '' '12/1/1959' '8/1/1955' '' '8/1/2002' '' '2/1/1935' '' '1/1/1960'

fdlable1: '7/1/1954' '7/1/2001' '1/1/1934' '12/1/1958' '7/1/1959' '4/1/1953' '8/1/1954' '8/1/2001' '2/1/1934' '1/1/1959' '8/1/1959' '5/1/1953' '9/1/1954' '9/1/2001' '3/1/1934' '2/1/1959' '9/1/1959' '6/1/1953' '10/1/1954' '10/1/2001' '4/1/1934' '3/1/1959' '10/1/1959' '7/1/1953' '11/1/1954' '11/1/2001' '5/1/1934' '4/1/1959' '11/1/1959' '8/1/1953' '12/1/1954' '12/1/2001' '6/1/1934' '5/1/1959' '12/1/1959' '9/1/1953' '1/1/1955' '1/1/2002' '7/1/1934' '6/1/1959' '1/1/1960' '10/1/1953' '2/1/1955' '2/1/2002' '8/1/1934' '7/1/1959' '2/1/1960' '11/1/1953' '3/1/1955' '3/1/2002' '9/1/1934' '8/1/1959' '3/1/1960' '12/1/1953' '4/1/1955' '4/1/2002' '10/1/1934' '9/1/1959' '4/1/1960' '1/1/1954'

How to get a matrix of serial date numbers?

The corresponding variable rates is:

rates = frates(:,1:2:23); 811 x 12

0.800000000000000   3.61000000000000    0.720000000000000   3.01000000000000
1.22000000000000    3.48000000000000    0.620000000000000   3.09000000000000
1.07000000000000    2.63000000000000    0.240000000000000   3.13000000000000
0.850000000000000   2.24000000000000    0.150000000000000   3.13000000000000
0.830000000000000   1.96000000000000    0.160000000000000   3.27000000000000
1.28000000000000    1.69000000000000    0.150000000000000   3.33000000000000
1.39000000000000    1.65000000000000    0.150000000000000   3.52000000000000
1.29000000000000    1.70000000000000    0.190000000000000   3.82000000000000
1.35000000000000    1.75000000000000    0.210000000000000   3.87000000000000
1.43000000000000    1.69000000000000    0.270000000000000   4.70000000000000

nahammond nahammond · Accepted Answer · 2020-12-03T03:12:08

datenum can not process empty data cells. On a smaller data set this works:

date_num = cellfun(@datenum, fdlable1(1:231,:), 'UniformOutput', false);

Using a cell array within datenum, convert to string with format before necessary?

1 Answers