nested for loop query - matlab

I am trying to do something rather simple, but can't seem to get it...
I have 3 cell-arrays with strings,
A = {'ConditionA'; 'ConditionB'; 'ConditionC'; 'ConditionD'};
B = {'Case1'; 'Case2'; 'Case3'; 'Case4'};
C = {'Rice'; 'Beans'; 'Carrots'; 'Cereal';'Tomato'; 'Cabbage';...
'Sugar'}
I want to produce a vector with the concatenated (strcat?) combinations, as it this were a "tree diagram", like:
strcat(A(1),B(1),C(1))
strcat(A(1),B(1),C(2))
strcat(A(1),B(1),C(3))
strcat(A(1),B(1),C(4))
strcat(A(1),B(1),C(5))
strcat(A(1),B(1),C(6))
strcat(A(1),B(1),C(7))
strcat(A(1),B(2),C(1))
So what the first elements I am trying to get are (in a column ideally):
ConditionACase1Rice
ConditionACase1Beans
ConditionACase1Carrots
ConditionACase1Cereal
ConditionACase1Tomato
ConditionACase1Cabbage
ConditionACase1Sugar
ConditionACase2Rice
etc etc etc...
I know that:
for i=1:length(A)
E(i) = strcat(A(i),B(1),C(1))
end
Works for one "level". I have tried:
for i=1:length(A)
for j=1:length(B)
for k=1:length(C)
P(i) = strcat(A(i),B(j),C(k));
end
end
end
But this doesn't work...
I would be really grateful if I could be helped with this.
Thanks in advance!

From what I understood, you want all possible combinations of the strings of the input arrays as specified. If so, simply replace your nested loops with the following:
P = cell(length(A)*length(B)*length(C),1);
t=1;
for i=1:length(A)
for j=1:length(B)
for k=1:length(C)
P(t) = strcat(A(i),B(j),C(k));
t = t+1;
end
end
end
For the input arrays,
>> A = {'ConditionA'; 'ConditionB'; 'ConditionC'; 'ConditionD'};
>> B = {'Case1'; 'Case2'; 'Case3'; 'Case4'};
>> C = {'Rice'; 'Beans'; 'Carrots'; 'Cereal';'Tomato'; 'Cabbage';'Sugar'};
The value of P would be:
>> P
P =
'ConditionACase1Rice'
'ConditionACase1Beans'
'ConditionACase1Carrots'
'ConditionACase1Cereal'
'ConditionACase1Tomato'
'ConditionACase1Cabbage'
'ConditionACase1Sugar'
'ConditionACase2Rice'
'ConditionACase2Beans'
'ConditionACase2Carrots'
'ConditionACase2Cereal'
'ConditionACase2Tomato'
'ConditionACase2Cabbage'
'ConditionACase2Sugar'
'ConditionACase3Rice'
'ConditionACase3Beans'
'ConditionACase3Carrots'
'ConditionACase3Cereal'
'ConditionACase3Tomato'
'ConditionACase3Cabbage'
'ConditionACase3Sugar'
'ConditionACase4Rice'
'ConditionACase4Beans'
'ConditionACase4Carrots'
'ConditionACase4Cereal'
'ConditionACase4Tomato'
'ConditionACase4Cabbage'
'ConditionACase4Sugar'
'ConditionBCase1Rice'
'ConditionBCase1Beans'
'ConditionBCase1Carrots'
'ConditionBCase1Cereal'
'ConditionBCase1Tomato'
'ConditionBCase1Cabbage'
'ConditionBCase1Sugar'
'ConditionBCase2Rice'
'ConditionBCase2Beans'
'ConditionBCase2Carrots'
'ConditionBCase2Cereal'
'ConditionBCase2Tomato'
'ConditionBCase2Cabbage'
'ConditionBCase2Sugar'
'ConditionBCase3Rice'
'ConditionBCase3Beans'
'ConditionBCase3Carrots'
'ConditionBCase3Cereal'
'ConditionBCase3Tomato'
'ConditionBCase3Cabbage'
'ConditionBCase3Sugar'
'ConditionBCase4Rice'
'ConditionBCase4Beans'
'ConditionBCase4Carrots'
'ConditionBCase4Cereal'
'ConditionBCase4Tomato'
'ConditionBCase4Cabbage'
'ConditionBCase4Sugar'
'ConditionCCase1Rice'
'ConditionCCase1Beans'
'ConditionCCase1Carrots'
'ConditionCCase1Cereal'
'ConditionCCase1Tomato'
'ConditionCCase1Cabbage'
'ConditionCCase1Sugar'
'ConditionCCase2Rice'
'ConditionCCase2Beans'
'ConditionCCase2Carrots'
'ConditionCCase2Cereal'
'ConditionCCase2Tomato'
'ConditionCCase2Cabbage'
'ConditionCCase2Sugar'
'ConditionCCase3Rice'
'ConditionCCase3Beans'
'ConditionCCase3Carrots'
'ConditionCCase3Cereal'
'ConditionCCase3Tomato'
'ConditionCCase3Cabbage'
'ConditionCCase3Sugar'
'ConditionCCase4Rice'
'ConditionCCase4Beans'
'ConditionCCase4Carrots'
'ConditionCCase4Cereal'
'ConditionCCase4Tomato'
'ConditionCCase4Cabbage'
'ConditionCCase4Sugar'
'ConditionDCase1Rice'
'ConditionDCase1Beans'
'ConditionDCase1Carrots'
'ConditionDCase1Cereal'
'ConditionDCase1Tomato'
'ConditionDCase1Cabbage'
'ConditionDCase1Sugar'
'ConditionDCase2Rice'
'ConditionDCase2Beans'
'ConditionDCase2Carrots'
'ConditionDCase2Cereal'
'ConditionDCase2Tomato'
'ConditionDCase2Cabbage'
'ConditionDCase2Sugar'
'ConditionDCase3Rice'
'ConditionDCase3Beans'
'ConditionDCase3Carrots'
'ConditionDCase3Cereal'
'ConditionDCase3Tomato'
'ConditionDCase3Cabbage'
'ConditionDCase3Sugar'
'ConditionDCase4Rice'
'ConditionDCase4Beans'
'ConditionDCase4Carrots'
'ConditionDCase4Cereal'
'ConditionDCase4Tomato'
'ConditionDCase4Cabbage'
'ConditionDCase4Sugar'
Let me know if you need further assistance.

I am not really familiar with matlab.. but maybe try something like this?
for A = {'ConditionA'; 'ConditionB'; 'ConditionC'; 'ConditionD'};
for B = {'Case1'; 'Case2'; 'Case3'; 'Case4'};
for C = {'Rice'; 'Beans'; 'Carrots'; 'Cereal';'Tomato'; 'Cabbage'; 'Sugar'}
P(i) = strcat(A(i),B(j),C(k));
end
end
end

{
x = 1;
for i=1:length(A)
for j=1:length(B)
for k=1:length(C)
P(x) = strcat(A(i),B(j),C(k));
x = x + 1;
end
end
end
}
Please basically check your code before posting to PO as this is a very simple debugging

Related

remove duplicates in a table (rexx language)

I have a question about removing duplicates in a table (rexx language), I am on netphantom applications that are using the rexx language.
I need a sample on how to remove the duplicates in a table.
I do have a thoughts on how to do it though, like using two loops for these two tables which are A and B, but I am not familiar with this.
My situation is:
rc = PanlistInsertData('A',0,SAMPLE)
TABLE A (this table having duplicate data)
123
1
1234
12
123
1234
I need to filter out those duplicates data into TABLE B like this:
123
1234
1
12
You can use lookup stem variables to test if you have already found a value.
This should work (note I have not tested so there could be syntax errors)
no=0;
yes=1
lookup. = no /* initialize the stem to no, not strictly needed */
j=0
do i = 1 to in.0
v = in.i
if lookup.v <> yes then do
j = j + 1
out.j = v
lookup.v = yes
end
end
out.0 = j
You can eliminate the duplicates by :
If InStem first element, Move the element to OutStem Else check all the OutStem elements for the current InStem element
If element is found, Iterate to the next InStem element Else add InStem element to OutStem
Code Snippet :
/*Input Stem - InStem.
Output Stem - OutStem.
Array Counters - I, J, K */
J = 1
DO I = 1 TO InStem.0
IF I = 1 THEN
OutStem.I = InStem.I
ELSE
DO K = 1 TO J
IF (InStem.I ?= OutStem.K) & (K = J) THEN
DO
J = J + 1
OutStem.J = InStem.I
END
ELSE
DO
IF (InStem.I == OutStem.K) THEN
ITERATE I
END
END
END
OutStem.0 = J
Hope this helps.

Matlab: two different variables take the same value

I want to implement recursion without a recursive function.
My code is the following:
for ff=1:6
for step=i:-1:1
if (step == maxStep)
R=-1;
if(isTM =='1')
R =1;
end
else
DielectricConst =cell2mat(valueArray(step,1));
Magnetic =cell2mat(valueArray(step,2));
currentFreq = cell2mat(frequencies(ff));
w = 2*3.1416*currentFreq;
kiz =w*(DielectricConst*Magnetic - E0*M0*sin(angle).*sin(angle))^(1/2);
DiConstPlusOne = cell2mat(valueArray(step+1,1));
MagPlusOne =cell2mat( valueArray(step+1,2));
kizPlusOne =w*(DiConstPlusOne*MagPlusOne - E0*M0*sin(angle).*sin(angle))^(1/2);
res =((DiConstPlusOne*kiz)-(DielectricConst*kizPlusOne))/((DiConstPlusOne*kiz)+(DielectricConst*kizPlusOne));
result =(res + R * exp(-((-1)^(1/2))*2*kizPlusOne*cell2mat( valueArray(step+1,3))))/(1+res*(R)*exp(-((-1)^(1/2))*2*kizPlusOne*cell2mat( valueArray(step+1,3))));
R=result;
end
% disp(R);
end
end
res and result values are always the same. Is it a pointer problem ?

Matlab) what should I put more with function for, sttrep, cell?

I want to make the results like this:
phraseblanks
phrasemat = Hello and how are you?
Hi there everyone!
How is it going?
WHazzup?
Phrase 1 had 4 blanks
Phrase 2 had 3 blanks
Phrase 3 had 2 blanks
Phrase 4 had 0 blanks
New phrasemat is :
Hello&and&how&are&you?
Hi&there&everyone!
How&is&it&going?
WHazzup?
so I made script "phraseblanks.m":
phrasemat = char('Hello and how are you?', ...
'Hi there everyone!', 'How is it going?', 'WHazzup?')
[r, c] = size(phrasemat);
for i = 1:r
phrasemat_new = cell(r, c);
howmany = countblanks(phrasemat(i, :));
fprintf('Phrase %d had %d blanks\n', i, howmany);
phrasemat(i,:) = strrep(phrasemat(i,:),' ','&')
phrasemat_new{i,:} = [phrasemat(i,:)];
end
fprintf('Changing one is %s\n', eval('phrasemat_new'));
script "countblanks.m":
function num = countblanks(phrase)
% countblanks returns the # of blanks in a trimmed string
% Format: countblanks(string)
num = length(strfind(strtrim(phrase), ' '));
end
and I keep having errors.
please help me..
I modified slightly your phraseblanks.m so that it works.
phrasemat = {'Hello and how are you?', ...
'Hi there everyone!', ...
'How is it going?', ...
'WHazzup?'};
r = numel(phrasemat);
phrasemat_new = cell(1, r);
for i = 1:r
howmany = countblanks(phrasemat{i});
fprintf('Phrase %d had %d blanks\n', i, howmany);
phrasemat{i} = strrep(phrasemat{i}, ' ', '&');
phrasemat_new(i) = phrasemat(i);
end
fprintf('Changing one is %s\n', phrasemat_new{:});
Obviously it could be written in a nicer, more "matlaby-way", but I didn't want to stride too far from your original version. Also you could consider using regular expressions, since if you have to spaces next to each other and you want to treat them as one blank space.

Recursive concatenation of Matlab structs

Is it somehow possible to concatenate two matlab structures recursively without iterating over all leaves of one of the structures.
For instance
x.a=1;
x.b.c=2;
y.b.d=3;
y.a = 4 ;
would result in the following
res = mergeStructs(x,y)
res.a=4
res.b.c=2
res.b.d=3
The following function works for your particular example. There will be things it doesn't consider, so let me know if there are other cases you want it to work for and I can update.
function res = mergeStructs(x,y)
if isstruct(x) && isstruct(y)
res = x;
names = fieldnames(y);
for fnum = 1:numel(names)
if isfield(x,names{fnum})
res.(names{fnum}) = mergeStructs(x.(names{fnum}),y.(names{fnum}));
else
res.(names{fnum}) = y.(names{fnum});
end
end
else
res = y;
end
Then res = mergeStructs(x,y); gives:
>> res.a
ans =
4
>> res.b
ans =
c: 2
d: 3
as you require.
EDIT: I added isstruct(x) && to the first line. The old version worked fine because isfield(x,n) returns 0 if ~isstruct(x), but the new version is slightly faster if y is a big struct and ~isstruct(x).

Prefix match in MATLAB

Hey guys, I have a very simple problem in MATLAB:
I have some strings which are like this:
Pic001
Pic002
Pic003
004
Not every string starts with the prefix "Pic". So how can I cut off the part "pic" that only the numbers at the end shall remain to have an equal format for all my strings?
Greets, poeschlorn
If 'Pic' only ever occurs as a prefix in your strings and nowhere else within the strings then you could use STRREP to remove it like this:
>> x = {'Pic001'; 'Pic002'; 'Pic003'; '004'}
x =
'Pic001'
'Pic002'
'Pic003'
'004'
>> x = strrep(x, 'Pic', '')
x =
'001'
'002'
'003'
'004'
If 'Pic' can occur elsewhere in your strings and you only want to remove it when it occurs as a prefix then use STRNCMP to compare the first three characters of your strings:
>> x = {'Pic001'; 'Pic002'; 'Pic003'; '004'}
x =
'Pic001'
'Pic002'
'Pic003'
'004'
>> for ii = find(strncmp(x, 'Pic', 3))'
x{ii}(1:3) = [];
end
>> x
x =
'001'
'002'
'003'
'004'
strings = {'Pic001'; 'Pic002'; 'Pic003'; '004'};
numbers = regexp(strings, '(PIC)?(\d*)','match');
for cc = 1:length(numbers);
fprintf('%s\n', char(numbers{cc}));
end;