I've an integer array
int(4) :: idate ! 1979 March 1st 00hrs
write(*,*)idate ! prints ' 0 3 1 1979'
I want idate to be saved in a different variable (integer/integer array only) which will print the date as:
1979030100
without changing it into char/strings.
Can this be done. Pardon me if it is trivial but I've spent quite a bit of my time on it.
You could do something like this:
integer :: date_as_int
...
date_as_int = idate(1)*10**6 + idate(2)*10**4 + idate(3)*10**2 + idate(4)
You might even get away with
date_as_int = sum(idate*10**[6,4,2,0])
or
date_as_int = dot_product(idate, 10**[6,4,2,0])
The square brackets syntax is from Fortran 2003. With older compilers [6,4,2,0] should be replaced by (/6,4,2,0/).
Related
I need to get numbers with a variable length out of a string and sum them.
The strings got the following format:
EH:NUMBER=SomeOtherStuff->Code
I'm extracting the code via RIGHT() and join with another table to get the group right, at the moment I'm using sum to get it together via date:
SUM(CASE WHEN (MONTH(data.DATE1) = 5 AND YEAR(data.DATE1) = YEAR(GETDATE())) THEN 1 ELSE 0 END) N'Mai',
I then need to sum the numbers from the string and not the number of rows.
Some Examples:
Month1 EH:1=24->ZTM
Month1 EH:4=13-21->LKm
Month2 EH:3=34,33,43->LKm
Month2 EH:7=12,92-29,29->LKm
Month2 EH:5=24-26,11,21,22->ZOL
What i need:
Material - Month1 - Month2
ZTM - 1 - 0
LKM - 4 - 10
ZOL - 0 - 5
Could you help me please?
Greetings
Short version:
What you are looking for is SUBSTRING.
Longer version:
To get the the sum of the numerical value of NUMBER you need think about how break it down.
I'd recommend following these steps:
Extract the NUMBER part from the string. This should be done with SUBSTRING (much like you extract Code with RIGHT). To get the start and and length och your substring use charindex ( or patindex if you like).
Convert the NUMBER part to a numerical value with cast (or convert or what you are familiar with)
Now you can do your aggregation.
So SUM(CAST(SUBSTRING(*this part you will have to figure out by yourself)) as correct numerical data type)).
I'll let you figure out the values to insert by yourself and would recommend to first find the positions of the delimiting characters, then extract the NUMBER part, then get the numerical value .... you get it .
This to gain a better understanding of what you are actually doing.
Cheers, and good luck with your assignment
Martin
Ok... I guess my brain has finally gone on vacation without me today. I have extracted 2 fields from a website and I get this string
vData = "Amount Owed [EXTRACT]$125.00[EXTRACT]
vData was declared as an array (string).
I split vData on [EXTRACT] and I end up with 2 string variables like this:
varA = "Amount Owed"
varB = "$125.00"
To parse varB, I use
Dim varC as Currency
varC = val(varB)
I want to use varC in an If statement:
If Val(VarC) <> 0 Then
I was expecting varC to be 125 but when I look at varC is 0. I can't figure out why varC = 0 and not 125.
Use CCur(varB) instead of Val(varB). CCur converts to a Currency type, so knows about $ and other things.
Explanation from the MS docs:
... when you use CCur, different decimal separators, different thousand separators, and various currency options are properly recognized depending on the locale setting of your computer.
Val is only looking for straight numbers:
The Val function stops reading the string at the first character it can't recognize as part of a number. Symbols and characters that are often considered parts of numeric values, such as dollar signs and commas, are not recognized.
I have a date cell array which is read from a csv file. The format is below:
date =
'2008.12.01'
'2008.12.02'
'2008.12.03'
'2008.12.04'
'2008.12.05'
... ...
And I want to:
turn the cell array to a string array,
use the strread() to read its "yyyy","mm" and "dd" value into 3 double array [year,mm,dd],
use the datenummx() to turn [year,mm,dd] into date seriel num.
After i use
date = char(date);
the date array become like this:
date =
2008.12.01
2008.12.02
2008.12.03
2008.12.04
2008.12.05
... ...
which I think the result is what i want...
But after I use the strread(), it gives me odd result.
[year,month,day]=strread(date,'%d%d%d','delimiter','.');
year =
-1
0
0
0
0
... ...
BUT if I use the code below, the strread() can give me the right answer:
s = sprintf('2008.12.01')
s =
2008.12.01
[year,month,day]=strread(s,'%d%d%d','delimiter','.')
year =
2008
month =
12
day =
1
And I checked in the matlab that both the "date" and "s" is a char array.(by using function 'ischar' and simply display both)...
But why do the strread() give differnt results?
Can anyone answer?
by the way, I use the MatLab v6.5.(for my own reason, so please don't comment by asking "why not use a higher version")....
Your problem is this line:
date = char(date);
It does not create an array of strings, there is no array of strings in matlab. It creates an array of chars. As you already noticed, your strread-line is fine if you input a single date, so input each date form your original cell array individually:
for idx=1:numel(date)
[year(idx),month(idx),day(idx)]=strread(date{idx},'%d%d%d','delimiter','.');
end
Preallocation of year, month and day improves the performance.
When trying the following concatenation:
for i=1:1:length(Open)
data(i,1) = Open(i);
data(i,2) = Close(i);
data(i,3) = High(i);
data(i,4) = Low(i);
data(i,5) = Volume(i);
data(i,6) = Adj_Close(i);
data(i,7) = cell2mat(dates(1,i));
end
Where all matrices but dates contain double values, and dates is a cell array with dates in the format '2001-01-01'. Running the code above, I get the following error:
??? Subscripted assignment dimension mismatch.
Error in ==> Test_Trades_part2 at 81
data(i,7) = cell2mat(dates(1,i));
The code above is tied to a master code which takes data from Yahoo Finance and then puts it in my SQL database.
A convenient way to store dates in completely numeric format is with datenum:
>> data(i,7) = datenum('2001-01-01');
>> disp(data(i,:))
0 0 0 0 0 0 730852
Whether this is useful to you depends on what you intend to do with the SQL database. Howeer, converting back to a string with MATLAB is straightforward with the datestr command:
>> datestr(730852,'yyyy-mm-dd')
ans =
2001-01-01
APPENDIX:
A serial date number represents a calendar date as the number of days that has passed since a fixed base date. In MATLAB, serial date number 1 is January 1, 0000.
Thank you all for the help!
I solved this issue using the following methodlogy (incorporating structs, should have thought of that .. stupid me):
data = [open, close_price, high, low, volume, closeadj];
s = struct('OpenPrice', data(:,1), 'ClosePrice', data(:,2), 'High', data(:,3), 'Low', data(:,4), 'Volume', data(:,5), 'Adj_Close', data(:,6), 'Dates', {dates});
This way, I enter all the values contained in the struct, circumventing the need to concatenate numeric and string matrices. Odd though, that is not allowed to have such matrices in on matrix; I would suppose that is the reason they created structs.
Before asking my question, here's a little background so you understand what I'm doing. I'm looking to analyze a very large data set (a little less than 2,000,000 rows). I've parsed the data set into Matlab and built a structure array from this data, giving names, dates, returns, etc for each asset i. Now, I would like to restrict my data set to being between two days, and Matlab doesn't seem to be particularly amenable to that kind of approach. One suggestion that was given to me was to take the dates, which are of the form MM/DD/YYYY and use a delimiter '/' to somehow build three integer arrays for my data structure (which I'd call stock(i).month, stock(i).day, and stock(i).year). However, nothing I'm doing seems to be working, and I'm very much stuck.
What I have been trying to do is something like the following:
%% Dates
fid = fopen('52c6d3831952b24a.csv');
C = textscan(fid, [repmat('%*s ',1,0),'%s %*[^\n]'], 'delimiter',',');
date = C{1}(2:end,1);
fclose(fid);
for i=1:numStock
locate = strcmp(uniquePermno{i},permno);
stock(i+1).date = date(locate);
end;
for i = 1:numStock
stock(i+1).date = char(stock(i+1).date);
D = textscan(stock(i+1).date, '%s %s %s', 'delimiter','/');
stock(i+1).month = D{1}(1:end);
stock(i+1).day = D{2}(1:end);
stock(i+1).year = D{3}(1:end);
end
I initially wanted to save them as integers (and was using %u instead), but I was getting a strange situation where most of my entries were just 0 and the non-zero ones were very large (obviously not what I expected). However, the above form returns the following error:
Error using textscan
Buffer overflow (bufsize = 4095) while reading string from
file (row 1 u, field 1 u). Use 'bufsize' option. See HELP TEXTSCAN.
44444444444444444444455555555555555555555566666666666666666666677777777777777777777778888888888888888888889999999999999999999990000000000000000000000011111111111111111112222222222222222222222111111111
Error in makeData_CRSP (line 87)
D = textscan(stock(i+1).date, '%s %s %s', 'delimiter','/');
So I'm honestly at a loss for how to approach this. What am I doing wrong? Seeing how I saved my dates vectors for my data structure, is this the best way to approach this problem?
You can use the datenum function to convert dates into numbers. The syntax is datenum(dateString, format). For example, if your dates are in the format YYYY MM DD then that would be
datenum('2012 12 04', 'yyyy mm dd')
Once you converted all your dates like that you can simply compare the resulting numbers using > and <:
>> datenum('2012 12 04', 'yyyy mm dd') > datenum('2012 12 03', 'yyyy mm dd')
ans =
1
>> datenum('2012 12 04', 'yyyy mm dd') > datenum('2012 12 05', 'yyyy mm dd')
ans =
0