Type 1 Cosine Transform

I want to use Type 1 Cosine Transform instead of the default Type 2. However, when I tried what suggested from Matworks: dct(x,'Type',1), it gave me the error

"Error using dct, Too many input arguments." May I ask what I am supposed to do? Thank you and I appreciate your help!

[David Goodmanson]

Hi LL,

I tried dct(1:10,'Type',1) and it works. You may want to try

which dct -all

and see what it says, in case there is a different dct floating around besides the standard one.

[Lan Liu]

I believed that I tried with the right dct. May I ask which version of Matlab you have, I have R2016a. Below are the message.

>> which dct -all

/Applications/MATLAB_R2016a.app/toolbox/images/images/private/dct.m % Private to images

/Applications/MATLAB_R2016a.app/toolbox/signal/signal/dct.m

>> dct(1:10,'Type',1)

Error using dct

Too many input arguments.

Thank you and I appreciate it!

[David Goodmanson]

I am using 2018b. Your Matlab path certainly looks to be appropriate. I wanted to try this with my archived 2016b but at that time I didn't have the signal processing toolbox, so I cannot. Maybe someone else will weigh in.

[Lan Liu]

Thank you David! I downloaded 2018b version and it worked perfectly! Thank you :=)

Answer 1

[Stephan]

Hi,

the option 'Type' was introduced in R2017a - see the release notes for Signal Processing Toolbox. To avoid this kind of issues, make sure to work with the documentation that matches the Matlab Relase you are using. The documentation you find first on mathworks.com is always the one for the current release. For the next few weeks this will be R2018b until the release R2019a will be published.

Best regards

Stephan