Datestr() transforms the matrix of days

I have a matrix with the number of days converted using datenum(). Now I want to convert back to the original date, but the result is wrong.The code is as follows:

day=[737433;737445;737457;737469;737481;737493;737505]
value=datestr(day(1:7),'yyyymmdd');
value=str2num(value);

The execution result is:

value=[101;102;103;104;105;106;107];

actually the results should be

[20190108;20190120;20190201;20190213;20190225;20190309;20190321]

How should I solve this problem? Thank you

Answer 1

[Star Strider]

I cannot reproduce that. I get what the reults should be (in R2020a):

day=[737433;737445;737457;737469;737481;737493;737505];
value=datestr(day(1:7),'yyyymmdd')
value=str2num(value)

producing:

value =

  7×8 char array

    '20190108'
    '20190120'
    '20190201'
    '20190213'
    '20190225'
    '20190309'
    '20190321'

and:

value =

    20190108
    20190120
    20190201
    20190213
    20190225
    20190309
    20190321

.

[sun]

I use R2017a, is it the problem of Matlab version？

[Walter Roberson]

It works for me in R2017a.

Note by the way that

>> char(101:107)

ans =

    'efghijk'

Perhaps that might give you ideas as to where the results came from?

    which -all str2num

[sun]

sir, I inserted some breakpoints for debugging, and found that actually datestr(day(1:7),‘yyyymmdd’) execution result is

[00000101'

'00000102'

'00000103'

'00000104'

'00000105'

'00000106'

'00000107']

At the same time, the execution result in the command line window is correct.

But the execution result in the script is wrong (as mentioned above). What is the reason?

[Walter Roberson]

At the time that happens, please show us the content of day(1) and also show us

which -all datestr

[Star Strider]

Walter — Thank you!