In matlab i'm coding a Ceaser Cipher, but the space shows up as a 'y' character.
How can I replace that with a space
case 4
disp('Breaking Ceaser Cipher')
cs = menu('Please Enter your Choice','Encryption','Decryption');
if cs==1
c = input('Enter the message: ','s');
sh = str2double(input('Enter shift: ','s'));
c=upper(c);
lc=length(c);
for i=1:lc
p(i)=int16(c(i))-65+sh;
end
p=mod(p,26)+97;
p=char(p);
disp( p)
end
end
output example:
Breaking Ceaser Cipher
Enter the message:
my name is jeff
Enter shift:
5
rdysfrjynxyojkk
Here we see that the encryption is correct, but the space is being replaced by 'y'. It does not replace the character 'y' when used as an input, the space bar somehow comes out as a 'y'.
I'v also tried using p2 = regexprep(c, 'y', ' ') in order to replace the 'y' string with space.Also looked into isspace function. No luck
You are halfway there:
spaces=isspace(c)
% make array of spaces
out=blanks(size(c));
% get array without spaces
c=c(~spaces);
% do stuff to c, without spaces.
p=mod(p,26)+97;
p=char(p);
% Fill p in corresponding locations
out(~spaces)=p;
Related
Can some one explain what this line here does? This is part of an old matlab code I need to reuse for my work
matdir = [params.ariens '-' num2str(dirtimes(ii))];
I'm especially confused about the '-' part. Thanks a lot in advance.
Single quotes are used to create a string literal so '-' simply creates a string containing the hyphen character. In MATLAB, [ ... ] performs horizontal concatenation so the line that you have shown concatenates the string stored in params.ariens, the character '-' and the number dirtimes(ii) converted to a string using num2str to creat one long string made up of those three strings.
For example:
c = ['abc', '-', 'def']
% abc-def
class(c)
% char
d = ['abc', '-', num2str(10)]
% abc-10
I have a set of documents containing pre-processed texts from html pages. They are already given to me. I want to extract only the words from it. I do not want any numbers or common words or any single letters to be extracted. The first problem I am facing is this.
Suppose I have a cell array :
{'!' '!!' '!!!!)' '!!!!thanks' '!!dogsbreath' '!)' '!--[endif]--' '!--[if'}
I want to make the cell array having only the words - like this.
{'!!!!thanks' '!!dogsbreath' '!--[endif]--' '!--[if'}
And then convert this to this cell array
{'thanks' 'dogsbreath' 'endif' 'if'}
Is there any way to do this ?
Updated Requirement : Thanks to all of your answers. However I am facing a problem ! Let me illustrate this (Please note that the cell values are extracted text from HTML documents and hence may contain non ASCII values) -
{'!/bin/bash' '![endif]' '!take-a-long' '!–photo'}
This gives me the answer
{'bin' 'bash' 'endif' 'take' 'a' 'long' 'â' 'photo' }
My Questions:
Why is bin/bash and take-a-long being separated into three cells ? Its not a problem for me but still why? Can this be avoided. I mean all words coming from a single cell being combined into one.
Notice that in '!–photo' there exists an non-ascii character â which esentially means a. Can a step be incorporated such that this transformation is automatic?
I noticed that the text "it? __________ About the Author:" gives me "__________" as a word. Why is this so ?
Also the text "2. areoplane 3. cactus 4. a_rinny_boo... 5. trumpet 6. window 7. curtain ... 173. gypsy_wagon..." returns a word as 'areoplane' 'cactus' 'a_rinny_boo' 'trumpet' 'window' 'curtain' 'gypsy_wagon'. I want the words 'a_rinny_boo' and ''gypsy_wagon to be 'a' 'rinny' 'boo' 'gypsy' 'wagon'. Can this be done ?
Update 1 Following all the suggestions I have written down a function which does most of the things except the above two newly asked questions.
function [Text_Data] = raw_txt_gn(filename)
% This function will convert the text documnets into raw text
% It will remove all commas empty cells and other special characters
% It will also convert all the words of the text documents into lowercase
T = textread(filename, '%s');
% find all the important indices
ind1=find(ismember(T,':WebpageTitle:'));
T1 = T(ind1+1:end,1);
% Remove things which are not basically words
not_words = {'##','-',':ImageSurroundingText:',':WebpageDescription:',':WebpageKeywords:',' '};
T2 = []; count = 1;
for j=1:length(T1)
x = T1{j};
ind=find(ismember(not_words,x), 1);
if isempty(ind)
B = regexp(x, '\w*', 'match');
B(cellfun('isempty', B)) = []; % Clean out empty cells
B = [B{:}]; % Flatten cell array
% convert the string into lowecase
% so that while generating the features the case sensitivity is
% handled well
x = lower(B);
T2{count,1} = x;
count = count+1;
end
end
T2 = T2(~cellfun('isempty',T2));
% Getting the common words in the english language
% found from Wikipedia
not_words2 = {'the','be','to','of','and','a','in','that','have','i'};
not_words2 = [not_words2, 'it' 'for' 'not' 'on' 'with' 'he' 'as' 'you' 'do' 'at'];
not_words2 = [not_words2, 'this' 'but' 'his' 'by' 'from' 'they' 'we' 'say' 'her' 'she'];
not_words2 = [not_words2, 'or' 'an' 'will' 'my' 'one' 'all' 'would' 'there' 'their' 'what'];
not_words2 = [not_words2, 'so' 'up' 'out' 'if' 'about' 'who' 'get' 'which' 'go' 'me'];
not_words2 = [not_words2, 'when' 'make' 'can' 'like' 'time' 'no' 'just' 'him' 'know' 'take'];
not_words2 = [not_words2, 'people' 'into' 'year' 'your' 'good' 'some' 'could' 'them' 'see' 'other'];
not_words2 = [not_words2, 'than' 'then' 'now' 'look' 'only' 'come' 'its' 'over' 'think' 'also'];
not_words2 = [not_words2, 'back' 'after' 'use' 'two' 'how' 'our' 'work' 'first' 'well' 'way'];
not_words2 = [not_words2, 'even' 'new' 'want' 'because' 'any' 'these' 'give' 'day' 'most' 'us'];
for j=1:length(T2)
x = T2{j};
% if a particular cell contains only numbers then make it empty
if sum(isstrprop(x, 'digit'))~=0
T2{j} = [];
end
% also remove single character cells
if length(x)==1
T2{j} = [];
end
% also remove the most common words from the dictionary
% the common words are taken from the english dicitonary (source
% wikipedia)
ind=find(ismember(not_words2,x), 1);
if isempty(ind)==0
T2{j} = [];
end
end
Text_Data = T2(~cellfun('isempty',T2));
Update 2
I found this code in here which tells me how to check for non-ascii characters. Incorporating this code snippet in Matlab as
% remove the non-ascii characters
if all(x < 128)
else
T2{j} = [];
end
and then removing the empty cells it seems my second requirement is fulfilled though the text containing a part of non-ascii characters completely disappears.
Can my final requirements be completed ? Most of them concerns the character '_' and '-'.
A regexp approach to go directly to the final step:
A = {'!' '!!' '!!!!)' '!!!!thanks' '!!dogsbreath' '!)' '!--[endif]--' '!--[if'};
B = regexp(A, '\w*', 'match');
B(cellfun('isempty', B)) = []; % Clean out empty cells
B = [B{:}]; % Flatten cell array
Which matches any alphabetic, numeric, or underscore character. For the sample case we get a 1x4 cell array:
B =
'thanks' 'dogsbreath' 'endif' 'if'
Edit:
Why is bin/bash and take-a-long being separated into three cells ? Its not a problem for me but still why? Can this be avoided. I mean all words coming from a single cell being combined into one.
Because I'm flattening the cell arrays to remove nested cells. If you remove B = [B{:}]; each cell will have a nested cell inside containing all of the matches for the input cell array. You can combine these however you want after.
Notice that in '!–photo' there exists an non-ascii character â which esentially means a. Can a step be incorporated such that this transformation is automatic?
Yes, you'll have to make it based on the character codes.
I noticed that the text "it? __________ About the Author:" gives me "__________" as a word. Why is this so ?
As I said, the regex matches alphabetic, numeric, or underscore characters. You can change your filter to exclude _, which will also address the fourth bullet point: B = regexp(A, '[a-zA-Z0-9]*', 'match'); This will match a-z, A-Z, and 0-9 only. This will also exclude the non-ASCII characters, which it seems like the \w* flag matches.
I think #excaza's solution would be the go-to approach, but here's an alternative one with isstrprop using its optional input argument 'alpha' to look for alphabets -
A(cellfun(#(x) any(isstrprop(x, 'alpha')), A))
Sample run -
>> A
A =
'!' '!!' '!!!!)' '!!!!thanks' '!!dogsbreath' '!)' '!--[endif]--' '!--[if'
>> A(cellfun(#(x) any(isstrprop(x, 'alpha')), A))
ans =
'!!!!thanks' '!!dogsbreath' '!--[endif]--' '!--[if'
To get to the final destination, you can tweak this approach a bit, like so -
B = cellfun(#(x) x(isstrprop(x, 'alpha')), A,'Uni',0);
out = B(~cellfun('isempty',B))
Sample run -
A =
'!' '!!' '!!!!)' '!!!!thanks' '!!dogsbreath' '!)' '!--[endif]--' '!--[if'
out =
'thanks' 'dogsbreath' 'endif' 'if'
I'm trying to make an algorithm in Matlab that scans the character array from left to right and if it encounters a space, it should do nothing, but if it encounters 2 consecutive spaces, it should start printing the remaining quantities of array from next line. for example,
inpuut='a bc d';
after applying this algorithm, the final output should have to be:
a bc
d
but this algorithm is giving me the output as:
a bc
d d
Also, if someone has got a more simpler algorithm to do this task, do help me please :)
m=1; t=1;
inpuut='a bc d';
while(m<=(length(inpuut)))
if((inpuut(m)==' ')&&(inpuut(m+1)==' '))
n=m;
fprintf(inpuut(t:(n-1)));
fprintf('\n');
t=m+2;
end
fprintf(inpuut(t));
if(t<length(inpuut))
t=t+1;
elseif(t==length(inpuut))
t=t-1;
else
end
m=m+1;
end
fprintf('\n');
OK I gave up telling why your code doesn't work. This is a working one.
inpuut='a bc d ';
% remove trailing space
while (inpuut(end)==' ')
inpuut(end)=[];
end
str = regexp(inpuut, ' ', 'split');
for ii = 1:length(str)
fprintf('%s\n', str{ii});
end
regexp with 'split' option splits the string into a cell array, with delimiter defined in the matching expression.
fprintf is capable of handling complicated strings, much more than printing a single string.
You can remove the trailing space before printing, or do it inside the loop (check if the last cell is empty, but it's more costly).
You can use regexprep to replace two consecutive spaces by a line feed:
result_string = regexprep(inpuut, ' ', '\n');
If you need to remove trailing spaces: use this first:
result_string = regexprep(inpuut, ' $', '');
I have a solution without using regex, but I assumed you wanted to print on 2 lines maximum.
Example: with 'a b c hello':
a b
c hello
and not:
a b
c
hello
In any case, here is the code:
inpuut = 'a b c';
while(length(inpuut) > 2)
% Read the next 2 character
first2char = inpuut(1:2);
switch(first2char)
case ' ' % 2 white spaces
% we add a new line and print the rest of the input
fprintf('\n%s', inpuut(3:end));
inpuut = [];
otherwise % not 2 white spaces
% Just print one character
fprintf('%s', inpuut(1))
inpuut(1) = [];
end
end
fprintf('%s\n', inpuut);
I need to input characters from a GUI but they need to be separated by spaces. Every time a new character is added, it should be appended to the existing array.
For example:
user enters 'a', the content of array is 'a'
if user enters 'b' next, the content of array is 'a b'
Edit 1
These lines of code should be inside the pushbutton1_callback function, so whenever the user presses the button, a new character should be added to static text; separated by a space.
Edit 2
My only line of code in here is:
letter = get(handles.edit1, 'string')
Without details I can provide a conceptual solution.
Initialize the variable that holds the text to:
txt = '';
Then the callback will do:
txt = strtrim(sprintf('%s %s',txt, get(handleToTextBox,'String')));
letter = get(handles.edit1, 'string');
global txt;
txt=[txt letter];
txt=[txt ' '];
set(handles.text1, 'string', txt);
That's how I solved it.
There is for example a big big score
for 2 hours
and there is need to see how many more before the end of
do output on the screen of the outer loop
but the values and there are many, such as 70 000
Question - how to remove a line break when printing to screen
not to receive 70 000 lines
and to see only the current display in one line?
Instead of using disp to display text to the screen, use fprintf, which requires you to enter line breaks manually.
Compare
>> disp('Hello, '), disp('World')
Hello,
World
with
>> fprintf('Hello, '), fprintf('World\n')
Hello, World
The \n at the end of 'World\n' signifies a line break (or newline as they're commonly called).
Try this function, which you can use in place of disp for a string argument. It displays to the command window, and remembers the message it has displayed. When you call it the next time, it first deletes the previous output from the command window (using ASCII backspace characters), then prints the new message.
In this way you only get to see the last message, and the command window doesn't fill up with old messages.
function teleprompt(s)
%TELEPROMPT prints to the command window, over-writing the last message
%
% TELEPROMPT(S)
% TELEPROMPT() % Terminate
%
% Input S is a string.
persistent lastMsg
if isempty(lastMsg)
lastMsg = '';
end
if nargin == 0
lastMsg = [];
fprintf('\n');
return
end
fprintf(repmat('\b', 1, numel(sprintf(lastMsg))));
fprintf(s);
lastMsg = s;