function returning vector in matlab - matlab
I have a function returning a vector in MatLab, the problem is that function should return a unsigned integer value, I've debugged my code and I realize that the variable galois_value turns into a vector when I do a bitand and a bitxor operation. I've tried to do a typecast to turn the vector into a unsigned value but doesn't works. I've tried to force a cast, but doesn't works too. Below the function:
function galois_value = galois_mul2( value )
hex = uint8(hex2dec('1B'));
temp = typecast(value, 'int8');
temp = bitshift(temp,-7);
temp = bitand(typecast(temp,'uint8'),hex);
galois_value = bitxor(bitshift(value,1),uint16(temp));
end
The correct output of this function should be (this output comes from a C code that is working) :
96
210
97
224
119
194
192
156
196
195
102
10
10
117
235
213
49
57
235
79
172
5
23
62
111
188
223
128
113
133
128
102
30
238
226
31
The output I get with the MatLab function:
96 96
210 210
353 378
224 224
375 364
194 194
192 192
156 156
196 196
451 472
102 102
10 10
10 10
373 366
491 496
469 462
305 298
313 290
491 496
335 340
172 172
261 286
279 268
62 62
367 372
188 188
479 452
128 128
369 362
389 414
128 128
102 102
30 30
238 238
226 226
287 260
The code to display and debug the function:
%Key
key = {'00','01','02','03','04','05','06','07','08','09','0a','0b','0c','0d','0e','0f'};
for n = 1 : 16
keyU(n)=uint16(hex2dec(key(n)));
end
%State
state = {'00','11','22','33','44','55','66','77','88','99','aa','bb','cc','dd','ee','ff'};
for n = 1 : 16
stateU(n)=uint16(hex2dec(state(n)));
end
%Sbox
sbox = {'63','7c','77','7b','f2','6b','6f','c5','30','01','67','2b','fe','d7','ab','76','ca','82','c9','7d','fa','59','47','f0','ad','d4','a2','af','9c','a4','72','c0','b7','fd','93','26','36','3f','f7','cc','34','a5','e5','f1','71','d8','31','15','04','c7','23','c3','18','96','05','9a','07','12','80','e2','eb','27','b2','75','09','83','2c','1a','1b','6e','5a','a0','52','3b','d6','b3','29','e3','2f','84','53','d1','00','ed','20','fc','b1','5b','6a','cb','be','39','4a','4c','58','cf','d0','ef','aa','fb','43','4d','33','85','45','f9','02','7f','50','3c','9f','a8','51','a3','40','8f','92','9d','38','f5','bc','b6','da','21','10','ff','f3','d2','cd','0c','13','ec','5f','97','44','17','c4','a7','7e','3d','64','5d','19','73','60','81','4f','dc','22','2a','90','88','46','ee','b8','14','de','5e','0b','db','e0','32','3a','0a','49','06','24','5c','c2','d3','ac','62','91','95','e4','79','e7','c8','37','6d','8d','d5','4e','a9','6c','56','f4','ea','65','7a','ae','08','ba','78','25','2e','1c','a6','b4','c6','e8','dd','74','1f','4b','bd','8b','8a','70','3e','b5','66','48','03','f6','0e','61','35','57','b9','86','c1','1d','9e','e1','f8','98','11','69','d9','8e','94','9b','1e','87','e9','ce','55','28','df','8c','a1','89','0d','bf','e6','42','68','41','99','2d','0f','b0','54','bb','16'};
for n = 1 : 256
sboxU(n)=uint16(hex2dec(sbox(n)));
end
%Rcon
rcon = {'01','02','04','08','10','20','40','80','1b','36'};
for n = 1 : 10
rconU(n)=uint16(hex2dec(rcon(n)));
end
%Main AES Data Loop
for round = 1 : 10
%Add key + sbox
for i = 1 : 16
stateU(i)= sboxU(bitxor(stateU(i),keyU(i))+1);
end
%Shift Rows
buf1 = stateU(2);
stateU(2) = stateU(6);
stateU(6) = stateU(10);
stateU(10) = stateU(14);
stateU(14) = buf1;
buf1 = stateU(3);
buf2 = stateU(7);
stateU(3) = stateU(11);
stateU(7) = stateU(15);
stateU(11) = buf1;
stateU(15) = buf2;
buf1 = stateU(16);
stateU(16) = stateU(12);
stateU(12) = stateU(8);
stateU(8) = stateU(4);
stateU(4) = buf1;
%Process mixcolumn for all rounds but the last one
if round < 10
for j = 0 : 3
%Compute the current index
buf4 = (bitshift(j,2));
%buf1
aux1 = bitxor(stateU(buf4+1),stateU(buf4+2));
aux2 = bitxor(stateU(buf4+3),stateU(buf4+4));
buf1 = bitxor(aux1,aux2);
%buf2
buf2 = stateU(buf4+1);
%buf3
buf3 = bitxor(stateU(buf4+1),stateU(buf4+2));
buf3 = galois_mul2(buf3);
disp(buf3);
end
end
end
The problem is in line 3 of galois_mul2 function
temp = typecast(value, 'int8');
since value has type uint16 output of typecast is two elements.
for e.g. output of typecast(uint16(5), 'int8') is 5 0
If you change all types in lines 3,8,13,18 of main and lines 3,6 of galois_mul2 function to uint8 the problem will be solved.
Related
Write a table object into csv in matlab
I have a table object in Matlab with cells as shown in the snapshot:
The cells inside Land and Seamark are as below:
The class of the objects are as below:
>> class(FileData.gTruth.LabelData.Land)
ans =
'cell'
>> class(FileData.gTruth.LabelData.Land{1,1})
ans =
'double'
>> class(FileData.gTruth.LabelData)
ans =
'table'
I tried some syntax like writetable and csvwrite but i am not getting the right format of output. The reading of the Land and Seamark as shown in the figure gets jumbled(reading is columnwise and not row-wise).
I want my output to be in this order:
[1063 126 115 86] [1 169 158 147;1 104 165 66;728 105 276 43;950 113 971 40;1 107 810 23;227 133 48 15;618 131 107 20] [562 220 33 51;1736 167 26 28;532 130 18 15;393 129 23 14]
Code so far:
writetable(FileData.gTruth.LabelData,'labelled1.txt','Delimiter' , ';');
You can simply use reshape on the transpose of the two-dimensional matrices to build a new table:
Ship = [1063 126 115 86]
Land = {[1 169 158 147;1 104 165 66; 728 105 276 43; 950 113 971 40; 1 107 810 23; 227 133 48 15; 618 131 107 20]}
Seamark = {[562 220 33 51; 1736 167 26 28; 532 130 18 15; 393 129 23 14]}
t = table(Ship,Land,Seamark);
t2 = table(t.Ship,reshape(t.Land{:}.',1,[]),reshape(t.Seamark{:}.',1,[]))
writetable(t2,'mycsv.csv','WriteVariableNames',false)
The first and only row of mycsv.csv file is:
1063 126 115 86 1 169 158 147 1 104 165 66 728 105 276 43 950 113 971 40 1 107 810 23 227 133 48 15 618 131 107 20 562 220 33 51 1736 167 26 28 532 130 18 15 393 129 23 14
I used the WriteVariableNames,false Name-Value pair to indicate that the variable names are not to be included in the first row of the file.
Matlab replace value with zero from matrix
I matrix A = [123 123 123 99 99 99 32 32 32 40 40 40 22 22 34 34 34 152 152 152 92 92 92 91 91 91 146 146 146 119 3 3 96 96 96 136 136 136 68 68 ] B = [40 68 119] How can I replace with zero value from A that have same value with B. required result: C = [123 123 123 99 99 99 32 32 32 0 0 0 22 22 34 34 34 152 152 152 92 92 92 91 91 91 146 146 146 0 3 3 96 96 96 136 136 136 0 0 ] thank you...
Use ismember to obtain a logical mask of values of A that are in B, and then use that as a logical index to make those entries zero: C = A; % define C equal to A C(ismember(A,B)) = 0; % make elements from B equal to 0 Or, in a single line: multiply A by a mask that equals 1 for elements not in B and 0 for elements in B: C = A.*~ismember(A,B); % multiply A by a mask to make elements from B equal to 0
I'd start down this road: C = A; for i = 1:numel(B) C(C == B(i)) = 0; end The third line uses logical indexing - C == 20 is a logical matrix, true where the element is 20, false otherwise, and C(C == 20) = 0 sets the true elements to 0.
Error in for loop in matlab
I have an error in the following forloop. I know because the end value of the first for is going to be changed and it is not acceptable for Matlab to change in inside iteration. But would you have any idea how to overcome to it? By the way I used while, but does not help me at all. Data are as follow: D = [ 2.39484592826072e-05 286 4.94140791861196e-05 161 5.07906972800045e-05 163 0.000103133134300751 141 0.000142755898501384 136 0.000143741615840070 152 0.000188072960663613 177 0.000203545320971960 1 0.000269110781516704 296 0.000333161025069404 293 0.000351184122591795 167 0.000393661764751196 299 0.000469154814856272 173 0.000516662289403544 181 0.000537612407901054 156 0.000698464342131732 246 0.000848447859349023 66 0.000875283151707512 75 0.00102377583629824 68 0.00110034589129900 277 0.00110693756077989 129 0.00120680501123819 87 0.00151080017572355 78 0.00159156469379168 248 0.00190852817897233 270 0.00192106167039306 133 0.00224677708557380 258 0.00246430115488258 264 0.00288772180685041 255 0.00299392149856582 81 0.00315341807121748 242 0.00327625233716732 27 0.00362308575885149 124 0.00434568780796603 220 0.00443389247698617 239 0.00470947127244510 60 0.00474015278667278 23 0.00481651908877289 230 0.00487750364266560 53 0.00510342992049100 56 0.00513758569662983 228 0.00515453564704144 121 0.00515656244518627 232 0.00526922882200147 8 0.00547349131456174 50 0.00553337871530176 117 0.00569159206242299 18 0.00620144292620718 13 0.00630382865700000 119 0.00755647842280271 92 0.00983041839684126 40 0.00997057619578698 98 0.0102611966834032 44 0.0103337998140422 100 0.0105132461082006 37 0.0106952804631761 109 0.0107424055503829 208 0.0109630950142485 111 0.0115094667290339 105 0.0119529682389369 107]; ymin= D(:,1); mean_value = 0.00773867192661190; criteria = min(ymin); kk = 1; diff = 60; and here is the code that I would have an error for the changing size_D which is expected. while criteria < mean_value if isempty(B) ind_crt = find(min(ymin)); B(kk,:) = D(ind_crt,:); D(ind_crt,:) = []; kk = kk + 1; end criteria = min(min(D)); size_D = size(D,1); for ii=1:size_D if D(ii,1) == criteria size_B = size(B,1); for jj = 1:size_B if abs(D(ii,2) - B(jj,2)) > diff B(kk,:) = D(ii,:); D(ii,:)= []; kk = kk + 1; end size_D = size_D -1; criteria = min(min(D)) end end end end Update: Here is the error: Attempted to access D(59,1); index out of bounds because size(D)=[58,2]. Error in local_minima (line 50) if D(ii,1) == criteria
Replace your for loop by a while loop, so that the code in the loop is run only if the condition ii<=size_D is verified: ii=0; while ii<=size_D ii=ii+1; %loop code instead of the for ii=1:size_D %loop code
Matlab getting point coordinates
How can I get the coordinates at a specific point? I want to get the X coordinate of the points with Y = 18.1 ; Y = 33; Y = 70 Those points need to lie on the function that I plot. Sample Code t = [0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180]; y = [0 5 9 19 25 32 46 65 79 90 100 115 123 141 153 159 160 171 181 185 193 200 205 211 215 220 223 222 225 224 228 231 231 228 235 234 231]; plot(t,y) , grid on
Unfortunately, you are trying to find the values of t associated with a y, and your function is not monotonic so we need to actually code up a mock linear interpolation. Note, there may be a better way, but I do not know of it right now. Try the following code where yVals are the values you want an associated t for, and possArray will include all values of t that may satisfy those conditions.
clc; close all; clear all;
t = [0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180];
y = [0 5 9 19 25 32 46 65 79 90 100 115 123 141 153 159 160 171 181 185 193 200 205 211 215 220 223 222 225 224 228 231 231 228 235 234 231];
plot(t,y)
grid on
hold on
yVals = [18.1,33,70,222.5,230];
possArray = cell(1,numel(yVals));
iter = 1;
for val = yVals;
poss = [];
possNum = 1;
for i = 1:numel(y)-1
if y(i) <= val && y(i+1) >= val
minDiff = val-y(i);
yDiff = y(i+1)-y(i);
percAlong = minDiff/yDiff;
poss(possNum) = (t(i+1)-t(i))*percAlong+t(i);
possNum = possNum+1;
end
end
possArray{iter} = poss;
iter = iter + 1;
end
colors = hsv(numel(yVals));
legendCell = cell(numel(yVals)+1,1);
legendCell{1} = 'Original Line';
for i = 1:numel(yVals)
plot(possArray{i},yVals(i)*ones(size(possArray{i})),...
'x','MarkerSize',10,'LineWidth',2,'Color',colors(i,:))
legendCell{i+1} = ['Values for Y = ' ,num2str(yVals(i))];
end
legend(legendCell)
hold off
As stated previously, this is linear interpolation, so if you need it to be more complicated that is on you, the concept should however be similar
UPDATE
Updated code above to be a little more clean, and added a plot indicating that multiple possibilities may arise for a single value, and that the code will return all possibilities.
subtracting two matrices in matlab, the negative values in result are substituted by zero
I have two matrices in matlab, > IRwindow = > > **183** 171 150 125 137 138 167 184 173 152 105 114 141 167 185 148 113 105 115 141 186 183 147 112 105 > > ILwindow = > > **201** 170 165 177 203 181 174 167 169 189 154 150 156 168 181 187 175 158 131 144 173 186 183 167 141 I want to subtract these two matrices element-wise and get the result; for example for first element (183 - 201= -18 ) BUT the output for this element gives zero. the outcome result will be as below: > IRwindow - ILwindow ans = **0** 1 0 0 0 0 0 17 4 0 0 0 0 0 4 0 0 0 0 0 13 0 0 0 0 how could I keep the real results? without getting zero for negatives in my result-matrix
Run the following example code: %# Create random matrices X = randi(100, 5, 5); Y = randi(100, 5, 5); %# Convert to strictly non-negative format X = uint8(X); Y = uint8(Y); %# Perform subtractions A = X - Y; %# Convert to double format X = double(X); Y = double(Y); %# Perform subtraction B = X - Y; For a given sample run: A = 0 15 36 0 0 0 0 0 0 3 0 0 0 25 0 13 0 15 0 0 0 49 0 0 14 while: B = -8 15 36 -4 -65 0 -47 -45 -11 3 -18 -17 -11 25 -52 13 -53 15 -15 -1 -35 49 -47 -8 14 You will notice that all the negative numbers in A have been replaced by 0, while the negative numbers in B are displayed correctly. Stated simply: if you use a numerical format that is not able to store negative numbers, then Matlab truncates at 0. The solution is to convert to a format that is able to accomodate "real" numbers (or a close approximation thereof) such as double, or perhaps in your case one of the int formats may be more appropriate, such as int8, int16, int32 or int64.
Another option is to use single or double on the subtraction in one line as follows: ans=double(IRwindow-ILwindow)
I dont get the same problem as you: I have this code: IRwindow = [ 183 171 150 125 137 138 167 184 173 152 105 114 141 167 185 148 113 105 115 141 186 183 147 112 105] ILwindow = [ 201 170 165 177 203 181 174 167 169 189 154 150 156 168 181 187 175 158 131 144 173 186 183 167 141] IRwindow - ILwindow and i get this output: IRwindow = 183 171 150 125 137 138 167 184 173 152 105 114 141 167 185 148 113 105 115 141 186 183 147 112 105 ILwindow = 201 170 165 177 203 181 174 167 169 189 154 150 156 168 181 187 175 158 131 144 173 186 183 167 141 ans = -18 1 -15 -52 -66 -43 -7 17 4 -37 -49 -36 -15 -1 4 -39 -62 -53 -16 -3 13 -3 -36 -55 -36 Check that you are creating your matrices are being created properly (as doubles and not as unsigned integers).