So I have arr = randi([0,20],20,1). I want to show: If there are numbers less than 5, fprintf('Yes\n') only once. Im using a for loop (for i = 1 : length(arr)) and indexing it.
As your description, maybe you need if statement within for loop like below
for i = 1:length(arr)
if arr(i) < 5
fprintf('Yes\n');
break
end
end
If you want to print Yes once, you can try
if any(arr < 5)
fprintf('Yes\n')
endif
If you don't want to use break, the code below might be an option
for i = 1:min(find(arr <5))
if (arr(i) < 5)
fprintf('Yes\n');
end
end
You can use a break statement upon finding the first value under 5 and printing the Yes statement.
Using a break Statement:
arr = randi([0,20],20,1);
for i = 1: length(arr)
if arr(i) < 5
fprintf("Yes\n");
break;
end
end
Extension:
By Using any() Function:
Alternatively, if you'd like to concise it down without the need for a for-loop the any() function can be used to determine if any values within the array meet a condition in this case arr < 5.
arr = randi([0,20],20,1);
if(any(arr < 5))
fprintf("Yes\n");
end
By Using a While Loop:
Check = 0;
arr = randi([0,20],20,1);
i = 1;
while (Check == 0 && i < length(arr))
if arr(i) < 5
fprintf("Yes\n");
Check = 1;
end
i = i + 1;
end
Related
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.
I'm looking for a way to stop iterating the just inner loop once a condition is met. I thought of using "continue" but it's not doing what i wanted.
"break" seems to break the entire loop including the outer loop.
So in my code, once the condition is met. I want to stop iterating j but i want to start iterating i again. Thank you,
for i in 0..<sortedArray.count{
for j in 1..<sortedArray.count{
if sortedArray[j] == sortedArray[i]{
//I want to skip iterating inner loop j from now. and back to iterating i
}
}
}
Break just breaks the inner loop.
e.g.
for var i in 0...2
{
for var j in 10...15
{
print("i = \(i) & j = \(j)")
if j == 12
{
break;
}
}
}
Output -->
i = 0 & j = 10
i = 0 & j = 11
i = 0 & j = 12
i = 1 & j = 10
i = 1 & j = 11
i = 1 & j = 12
i = 2 & j = 10
i = 2 & j = 11
i = 2 & j = 12
The nested index loop and subsequent element access by index approach (anArray[accessByThisIndex]) is kind of C++'ish rather than Swifty. Depending on you application, you can make good use of neat features in Swift to achieve your goal.
E.g., assuming (based on the anme of your array) your array is sorted,
let sortedArray = [2, 5, 7, 9]
for i in sortedArray {
for j in sortedArray where j <= i {
print(j)
}
print("-----")
}
/* 2
-----
2
5
-----
2
5
7
-----
2
5
7
9
----- */
Note that we don't care about the indices of the array above, instead accessing the elements of the array directly in the for ... in (... where ...) loop(s).
Another alternatively coulkd make use of prefixUpTo(:_)
for i in 1...sortedArray.count {
sortedArray.prefixUpTo(i).forEach {
print($0)
}
print("-----")
}
/* same printout as above */
I'm quite new to Matlab so excuse me for the basic question.
I need to make a for-loop that repeats it's self 384 times.
So :
for i=1:384
I now need the for loop to check if 2 certain variables have the value 1 through 10, and then let them store this in a new variable with that value.
So:
if x==1
somevariable = 1
elseif x== 2
saomevariable = 2
..
..
..
elseif y = 1
someothervariable = 1
etc etc.
Is there a way to write this more efficient?
Thank you!
The first think you can do is:
if(x >= 1 && x <= 10)
somevariable=x;
end
if(y >= 1 && y <= 10)
someohtervariable=y;
end
If you could post more information about "x" and "y", perhaps your script can be further "improved".
Hope this helps.
Normally this function should give me the values 1, 2, 3 or 4. but when I use it, I get 0, 1 or 2. Could you help me to know where is the problem:
function Vecteur_retour = var_Test(Test)
AA = Test;
var_Test = zeros(1,2000);
for i=3:1:2000
if AA(i)<=AA(i-1) && AA(i-1)<=AA(i-2)
var_Test(i)=1;
else
if AA(i)<=AA(i-1) && AA(i-1)>AA(i-2)
var_Test(i)=2;
if AA(i)>AA(i-1) && AA(i-1)<=AA(i-2)
var_Test(i)=3;
else
if AA(i)>AA(i-1) && AA(i-1)>AA(i-2)
var_Test(i)=4;
end
end
end
end
end
Vecteur_retour = var_Test;
Vector comparisons will be much faster:
var_Test = ones(1,2000);
delta_Test = diff(Test);
var_Test([0 0 delta_Test(1:end-1)] > 0) = 2;
var_Test([0 delta_Test] > 0) = var_Test([0 delta_Test] > 0) + 2;
var_Test(1:2) = 0;
Probably because you never reach the cases var_Test(i) = 3 or var_Test(i) = 4.
You have a problem with your if and end blocks. The way you have it, case 3 is only reached if case 2 is hit first, but these are contradictory.
You want code more like.
function Vecteur_retour = var_Test(Test)
AA = Test;
var_Test = zeros(1,2000);
for i=3:1:2000
if AA(i)<=AA(i-1) && AA(i-1)<=AA(i-2)
var_Test(i)=1;
else
if AA(i)<=AA(i-1) && AA(i-1)>AA(i-2)
var_Test(i)=2;
else % you forgot this else
if AA(i)>AA(i-1) && AA(i-1)<=AA(i-2)
var_Test(i)=3;
else
if AA(i)>AA(i-1) && AA(i-1)>AA(i-2)
var_Test(i)=4;
end
end
end
end
end
Vecteur_retour = var_Test;
Careful indentation would have helped here.
I have some code that is taking a long time to run(several hours) and I think it is because it is doing a lot of comparisons in the if statement. I would like it to run faster, does anyone have any helpful suggestions to improve the runtime? If anyone has a different idea of what is slowing the code down so I could try and fix that it would be appreciated.
xPI = zeros(1,1783);
argList2 = zeros(1,1783);
aspList2 = zeros(1,1783);
cysList2 = zeros(1,1783);
gluList2 = zeros(1,1783);
hisList2 = zeros(1,1783);
lysList2 = zeros(1,1783);
tyrList2 = zeros(1,1783);
minList= xlsread('20110627.xls','CM19:CM25');
maxList= xlsread('20110627.xls','CN19:CN25');
N = length(pIList);
for i = 1:N
if (argList(i)>= minList(1) && argList(i) <= maxList(1)) ...
&& (aspList(i)>= minList(2) && aspList(i) <= maxList(2)) ...
&& (cysList(i)>= minList(3) && cysList(i) <= maxList(3)) ...
&& (gluList(i)>= minList(4) && gluList(i) <= maxList(4)) ...
&& (hisList(i)>= minList(5) && hisList(i) <= maxList(5)) ...
&& (lysList(i)>= minList(6) && lysList(i) <= maxList(6)) ...
&& (tyrList(i)>= minList(7) && tyrList(i) <= maxList(7))
xPI(i) = pIList(i);
argList2(i) = argList(i);
aspList2(i) = aspList(i);
cysList2(i) = cysList(i);
gluList2(i) = gluList(i);
hisList2(i) = hisList(i);
lysList2(i) = lysList(i);
tyrList2(i) = tyrList(i);
disp('passed test');
end
end
You can try vectorising the code; I have made up some sample data sets and duplicated some of the operations you're performing below.
matA1 = floor(rand(10)*1000);
matB1 = floor(rand(10)*1000);
matA2 = zeros(10);
matB2 = zeros(10);
minList = [10, 20];
maxList = [100, 200];
indicesToCopy = ( matA1 >= minList(1) ) & ( matA1 <= maxList(1) ) & ( matB1 >= minList(2) ) & ( matB1 <= maxList(2) );
matA2(indicesToCopy) = matA1(indicesToCopy);
matB2(indicesToCopy) = matB1(indicesToCopy);
No idea whether this is any faster, you'll have to try it out.
EDIT:
This doesn't matter too much since you're only making two calls, but xlsread is horribly slow. You can speed up those calls by using this variant syntax of the function.
num = xlsread(filename, sheet, 'range', 'basic')
The catch is that the range argument is ignored and the entire sheet is read, so you'll have to mess with indexing the result correctly.
Use the profiler to see which lines or functions are using the most execution time.
You can probably get a huge increase in execution speed by vectorizing your code. This means using operations which operate on an entire vector at once, instead of using a for-loop to iterate through it. Something like:
% make a logical vector indicating what you want to include
ii = (argList >= minList(1) & argList <= maxList(1)) & ...
% use it
argList2(ii) = arglist(ii); % copies over every element where the corresponding ii is 1
...