MATLAB: How to discard all punctuation from a text file

Question

Hello, I need a MATLAB code to discard all punctuation and signs from a text file.I want to keep only characters and numbers.Thanks.

Answer 1

Star Stride is right but perhaps Fateme wants to keep the spaces, because space is not punctuation spaces will help reading the resulting string. The initial string

str1 = 'Hello, I need 1 MATLAB code to discard all punctuation, and signs from 9 text files.'
Lstr1=length(str1)

the characters that have to remain are

str_space='\s'
str_caps='[A-Z]'
str_ch='[a-z]'
str_nums='[0-9]'

their respective positions within str1 are

ind_space=regexp(str1,str_space)
ind_caps=regexp(str1,str_caps)
ind_chrs=regexp(str1,str_ch)
ind_nums=regexp(str1,str_nums)
mask=[ind_space ind_caps ind_chrs ind_nums]

now let's find the position of all punctuation characters

num_str2=1:1:Lstr1
num_str2(mask)=[]

now num_str2 contains the positions of punctuation characters to remove

str3=str1
str3(num_str2)=[]

str3 contains the resulting string without any other character than alphabetical characters and numbers.

str3 =
Hello I need 1 MATLAB code to discard all punctuation and signs from 9 text files

Hope it helps in your reading.

John

jgb2012@sky.com