Error when using DPABI-standardization function for single image

Submitted by guiziwu on Thu, 02/21/2019 - 02:36

Dear all,

When I try to use DPABI-standardization function, I put one image for a single subject and then run the function. It appears the following error:

 Attempted to access Prctile_25_75(2,:); index out of bounds because size(Prctile_25_75)=[1,3].

Error in y_Standardization (line 86)
Median_AllSub = Prctile_25_75(2,:)';

 

However, when I entered multiple subjects' images, the problem solved. I am wondering whether there is anything needed to be fixed in this script?

 

Thank you so much!

 

Best wishes,

Mengxia

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Forums:

YAN Chao-Gan

Wed, 03/06/2019 - 23:05

You can not do this type of standardizatoin on a single image.

guiziwu

Sun, 03/17/2019 - 08:04

Thanks Dr. Yan for replying! I am using z-standardzation (z=(x-mean(x))./std(x)). So do you mean if I use this function, I am using the images from the whole group to get the mean and standadzation deviation, rather than calculating the z score on a single subject?

YAN Chao-Gan

Sun, 03/24/2019 - 09:33

The mean is the mean value across all voxels within the mask.

It should calculate z standardization for a single image.

However, the current version also calcuates other parameters for other kinds of standardization at the begining, thus it will give an error report.

guiziwu

Wed, 03/27/2019 - 01:55

That's clear and helpful. Thank you so much for the reply~