I suspect my question has a very simple answer, and yet I cannot find an answer that I understand in searching all over the site.
Ticker1 = an array of stock prices (1 to 2542)
PctChg1 = an array which I hope will ultimately hold the results of
(Price_last / Price_prev) - 1
i = counter
Code:
For i = 2 To UBound(Ticker1)
PctChg1(i, 1) = Ticker1(i, 1) / Ticker1(i - 1, 1) - 1
Next i
Something about the Ticker1(i - 1, 1) part it does not like - I have fooled around with ranges as well and cannot make sense of this. I don't know why it thinks I am dividing by a number that isn't there - if i am starting at point 2 of the array, why wouldn't I be able to reference point 1 ?
For i = 2 To UBound(Ticker1)
If Val(Ticker1(i - 1, 1)) <> 0 Then PctChg1(i, 1) = Ticker1(i, 1) / Ticker1(i - 1, 1) - 1
Next i
This works, but I still have not established why i-1 generates errors when I start the calculation on data point i=2.
Related
I have the following problem in my simulation.
A is an array 24 x 2. I am going to split it and get 4 or 12 array. It means that I group 6 or 2 array. It will be ok, if I use even "split" coefficient. If it is odd, I can"t split A.[ I can't group 5 or 7, because of 24/5=4*5 + 4 ( or 5*5 -1) or 24/7=7*3+3.
That's why I going to do the following:
If I have 24 x 2 and need group every 5 together:
block 1 : A(1,:), A(2,:),A(3,:),A(4,:),A(5,:)
block 2 : A(6,:), A(7,:),A(8,:),A(9,:),A(10,:)
block 3 : A(11,:), A(12,:),A(13,:),A(14,:),A(15,:)
block 4 : A(16,:), A(17,:),A(18,:),A(19,:),A(20,:)
block 5 : A(21,:), A(22,:),A(23,:),A(24,:), ?
As you can see the 5th block is not full, Matlab gives me an error. My idea is to create A(25,:)=0. For my simulation it will be ok.
I am going to simulate it as function:
A=rand(m,n)
w- # number of a vector that i would like group together ( in ex., it is `5`)
if mod(w,2)==0
if mod(m,2)==0
% do....
else
% remainder = 0
end
else
if mod(m,2)==0
% remainder = 0
else
%do...
end
I was going to simulate like above, but then I have noticed that it doesn't work. Because 24/10 = 2*10+4. So I should write something else
I can find the reminder as r = rem(24,5). As an example above, MatLab gives me r=4. then I can find a difference c= w-r =1 and after that, I don't know how to do that.
Could you suggest to me how to simulate such a calculation?
Determine the number of blocks needed, calculate the virtual amount of rows needed to fill these blocks, and add as many zero rows to A as the difference between the virtual and actual amount of rows. Since you didn't mention, what the actual output should look like (array, cell array, ...), I chose a reshaped array.
Here's the code:
m = 24;
n = 2;
w = 5;
A = rand(m, n)
% Determine number of blocks
n_blocks = ceil(m / w);
% Add zero rows to A
A(m+1:w*n_blocks, :) = 0
% Reshape A into desired format
A = reshape(A.', size(A, 1) / n_blocks * n, n_blocks).'
The output (shortened):
A =
0.9164959 0.1373036
0.5588065 0.1303052
0.4913387 0.6540321
0.5711623 0.1937039
0.7231415 0.8142444
0.9348675 0.8623844
[...]
0.8372621 0.4571067
0.5531564 0.9138423
A =
0.91650 0.13730
0.55881 0.13031
0.49134 0.65403
0.57116 0.19370
0.72314 0.81424
0.93487 0.86238
[...]
0.83726 0.45711
0.55316 0.91384
0.00000 0.00000
A =
0.91650 0.13730 0.55881 0.13031 0.49134 0.65403 0.57116 0.19370 0.72314 0.81424
0.93487 0.86238 0.61128 0.15006 0.43861 0.07667 0.94387 0.85875 0.43247 0.03105
0.48887 0.67998 0.42381 0.77707 0.93337 0.96875 0.88552 0.43617 0.06198 0.80826
0.08087 0.48928 0.46514 0.69252 0.84122 0.77548 0.90480 0.16924 0.82599 0.82780
0.49048 0.00514 0.99615 0.42366 0.83726 0.45711 0.55316 0.91384 0.00000 0.00000
Hope that helps!
I'm trying to create a program which will calculate the same date in three different ways. I'm currently stuck on calculating the day of the week, as I need this to calculate the ISO week day. I've got an algorithm that I can use, and it is the one which I've got in my code, with the only difference being that the % sign in my code is replaced by the word "mod" in the algorithm.
When I run this, I get an error saying "Expected expression before % token". I've looked this up but didn't find any results. I've also tried to look at other ways of doing it, and found the Sakomoto Algorithm, but I don't exactly understand how that works. For a possible solution, I was thinking that I maybe need to create a function called mod, but I'm not entirely sure what I would need to put in there.
int day_of_the_week(int year)
{
int week_day;
week_day = %(1+5 * %(year - 1, 4) + 4 * %(year - 1, 100) + 6 * %(year-1,
400), 7);
printf("The day of the week is %d\n", week_day);
return 0;
}
Gauss'
R(1 + 5R(A - 1, 4) + 4R(A - 1, 100) + 6R(A - 1, 400), 7)
should be equivalent to
int week_day = (1 + 5 * (year - 1) % 4) + 4 * ((year - 1) % 100) + 6 * ((year - 1) % 400) % 7;
I created an array to speed up this but it seems to take forever to run still. Is there are way to say once the first If is satisfied move to next i? It seems to find the match (always only one) but still search through all of the annualArray.
Do give detail i have ID's on one table and want to find the matching ID on another table, then pull the date from the second table and put it into the first table (and subtract by todays date)
Set report = ActiveWorkbook.Worksheets("Report")
Set uwat = ActiveWorkbook.Worksheets("UWAT")
For i = 2 To report.UsedRange.Rows.Count
For Z = 2 To annual.UsedRange.Rows.Count
annualArray1 = Worksheets("Annual").Range("B1:T2000").Value
If CLng(report.Cells(i, 1)) = annualArray1(Z, 1) And annualArray1(Z, 19) <> "" Then
report.Cells(i, 19) = Date - CDate(Mid(annualArray1(Z, 19), 16, 10))
End If
Next Z
Next i
I have an issue. I have values in a workbook that are getting read into an array. The values come from an XML list so sometimes can be numbers or text, and if they are numbers in text format ("1" for example), they need to be converted to number format, so I multiply them by 1. If the value is text "LS" for example, I am trying to use an error handler to keep the value as "LS".
I have developed the code below: It works once, but the next time I use a similar method (with 'Dummy2') the code it produces a 'Type Mismatch' error.
On Error GoTo Dummy1
For i = 1 To nrows1 - 1
If (Worksheets("Import").Cells(i + 1, 26) * 1 = "") Then
Dummy1:
Table1(i, 1) = Worksheets("Import").Cells(i + 1, 26)
Else
Table1(i, 1) = Worksheets("Import").Cells(i + 1, 26) * 1
End If
Next
On Error GoTo 0
I also tried Clearing Err after the above code with no success.
Please help!
You can use the IsNumeric function:
Sub test3()
Dim Test As Variant
Dim i As Long
For i = 1 To nrows1 - 1
Test = Worksheets("Import").Cells(i + 1, 26)
If IsNumeric(Test) Then
Table1(i, 1) = Test * 1
Else
Table1(i, 1) = Test
End If
Next
End Sub
use VAL(Worksheets("Import").Cells(i + 1, 26)) to determine if it is a Number or not. VAL will give you 0 for "LS".
You could try TryParse functions - but not sure if its available in your version of VBA
I have an array with a set of chronological serial numbers and another source array with random serial numbers associated with a numeric value. The code creates a new cell array in MATLAB with the perfectly chronological serial numbers in one column and in the next column it inserts the associated numeric value if the serial numbers match in both original source arrays. If they don't the code simply copies the previous associated value until there is a new match.
j = 1;
A = {random{1:end,1}};
B = cell2mat(A);
value = random{1,2};
data = cell(length(serial), 1);
data(:,1) = serial(:,1);
h = waitbar(0,'Please Wait...');
steps = length(serial);
for k = 1:length(serial)
[row1, col1, vec1] = find(B == serial{k,1});
tf1 = isempty(vec1);
if (tf1 == 0)
prices = random{col1,2};
data(j,2) = num2cell(value);
j = j + 1;
else
data(j,2) = num2cell(value);
j = j + 1;
end
waitbar(k/steps,h,['Please Wait... ' num2str(k/steps*100) ' %'])
end
close(h);
Right now, the run-time for the code is approximately 4 hours. I would like to make this code run faster. Please suggest any methods to do so.
UPDATE
source input (serial)
1
2
3
4
5
6
7
source input (random)
1 100
2 105
4 106
7 107
desired output (data)
SR No Value
1 100
2 105
3 105
4 106
5 106
6 106
7 107
Firstly, run the MATLAB profiler (see 'doc profile') and see where the bulk of the execution time is occuring.
Secondly, don't update the waitbar on every iteration> Particularly if serial contains a large (> 100) number of elements.
Do something like:
if (mod(k, 100)==0) % update on every 100th iteration
waitbar(k/steps,h,['Please Wait... ' num2str(k/steps*100) ' %'])
end
Some points:
Firstly it would help a lot if you gave us some sample input and output data.
Why do you initialize data as one column and then fill it's second in the loop? Rather initialize it as 2 columns upfront: data = cell(length(serial), 2);
Is j ever different from k, they look identical to me and you could just drop both the j = j + 1 lines.
tf1 = isempty(vec1); if (tf1 == 0)... is the same as the single line: if (!isempty(vec1)) or even better if(isempty(vec1)) and then swap the code from your else and your if.
But I think you can probably find a fast vecotrized solution if you provide some (short) sample input and output data.