I have a matrix A declared as real :: A(7,8) and intialised so that all entries are 0.0.
The following command does not provide any compiling errors.
A(::2,3) = -1.0
I realise that the columns affected will be only column 3.
What about the rows? Does ::2 mean rows 1 and 2? Or something else?
I printed out the matrix, but couldn't understand the pattern produced.
Here (for completeness):
do, i=1,7
write(*, "(f5.2)") ( A(i,j), j=1,8 )
enddo
0.00 i = 1
0.00
-1.00
0.00
0.00
0.00
0.00
0.00 ----
0.00 i = 2
0.00
0.00
0.00
0.00
0.00
0.00
0.00 ----
0.00 i = 3
0.00
-1.00
0.00
0.00
0.00
0.00
0.00 ----
0.00 i = 4
0.00
0.00
0.00
0.00
0.00
0.00
0.00 ----
0.00 i = 5
0.00
-1.00
0.00
0.00
0.00
0.00
0.00 ----
0.00 i = 6
0.00
0.00
0.00
0.00
0.00
0.00
0.00 ----
0.00 i = 7
0.00
-1.00
0.00
0.00
0.00
0.00
0.00
Looking at it now, it looks like it starts at i=1 and adds 2 to i until it reaches the bounds of the matrix. Is this correct?
Does this mean that ::2 is equivalent to 1:7:2 ("from 1 to 7 with a step of 2)?
Looking at the documentation, we see:
print array-expression [first-expression : last-expression : stride-expression]
where:
array-expression Expression that should evaluate to an array type.
first-expression First element in a range, also first element to be
printed. Defaults to lower bound.
last-expression Last element in a range, but might not be the last
element to be printed if stride is not equal to 1. Defaults to upper
bound.
stride-expression Length of the stride. Defaults to 1.
So if first-expression and last-expression are omitted, they default to lower bound and upper bound respectively.
Yes, that's right - it's the same as 1:7:2, as you can see from the output, it's setting the 3rd element in the sub-array to -1 for every 2nd sub array
Related
I was writing a Powershell script using a pipeline with a Process block and it started doing something unexpected: listing all the running processes and then dumping the script contents. I kept minimizing the script to try to figure out what was going on and ended up with this:
[CmdletBinding()]
Param()
$varname = "huh"
Process
{
# nothing here
}
So it looks like this:
PS /Volumes/folder> cat ./test.ps1
[CmdletBinding()]
Param()
$varname = "huh"
Process
{
# nothing here
}
PS /Volumes/folder> pwsh ./test.ps1
NPM(K) PM(M) WS(M) CPU(s) Id SI ProcessName
------ ----- ----- ------ -- -- -----------
0 0.00 0.00 0.00 0 639
0 0.00 0.00 0.00 1 1
0 0.00 0.00 0.00 60 60
0 0.00 0.00 0.00 61 61
0 0.00 0.00 0.00 65 65
0 0.00 0.00 0.00 67 67
0 0.00 0.00 0.00 68 68
0 0.00 0.00 0.00 69 69
0 0.00 0.00 0.00 71 71
0 0.00 0.00 0.00 73 73
0 0.00 0.00 0.00 75 75
0 0.00 25.60 75.82 68475 1 Activity Monito
0 0.00 11.74 97.63 1053 1 Adobe Crash Han
0 0.00 11.76 97.62 1084 1 Adobe Crash Han
0 0.00 11.69 97.64 1392 1 Adobe Crash Han
0 0.00 112.50 83.59 973 1 Adobe Desktop S
0 0.00 11.94 97.31 986 1 AdobeCRDaemon
0 0.00 16.95 105.99 966 1 AdobeIPCBroker
0 0.00 61.52 168.92 721 1 Adobe_CCXProces
0 0.00 18.57 3.01 454 1 adprivacyd
0 0.00 16.46 23.16 700 1 AGMService
0 0.00 13.65 4.43 701 1 AirPlayUIAgent
--snip--
0 0.00 9.11 12.72 89003 …03 VTDecoderXPCSer
0 0.00 13.32 4.69 418 1 WiFiAgent
0 0.00 12.21 1.58 543 543 WiFiProxy
# nothing here
I haven't done much in Powershell for a long time so if this is something stupid simple I'm going to laugh but I couldn't find anything searching the net.
Can someone tell me what's happening?
In order to use a process block (possibly alongside a begin, end, and, in v7.3+, the clean block), there must not be any code OUTSIDE these blocks - see the conceptual about_Functions help topic.
Therefore, remove $varname = "huh" from the top-level scope of your function body (possibly move it into one of the aforementioned blocks).
As for what you tried:
By having $varname = "huh" in the top-level scope of your function body, you've effectively made the function in one whose code runs in an implicit end block only.
process - because it is on its own line - was then interpreted as a command, which - due to the best-avoided default-verb logic - was interpreted as an argument-less call to the Get-Process cmdlet.
The output therefore included the list of all processes on your system.
The { ... } on the subsequent lines was then interpreted as a script block literal. Since that script block wasn't invoked, it was implicitly output, which results in its stringification, which is its _verbatim content, excluding { and }, resulting in output of the following string:
# nothing here
I have a big text file which gives me solar irradiance according to latitude and longitude with a 22 year monthly average.
These data are regional averages; not point data.
Created: March 12, 2008
Lat Lon Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
-90 -180 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -179 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -178 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -177 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -176 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -175 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -174 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -173 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -172 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -171 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -170 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -169 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -168 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -167 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -166 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -165 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -164 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -163 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -162 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
-90 -161 9.63 5.28 0.75 0.00 0.00 0.00 0.00 0.00 0.10 3.24 8.28 10.97 3.19
Now, I want to find monthly average for lat=-90 & long=-166. How can I call them into my workspace variable?
Also, while working in matlab, will it be better to call this whole text file when we run the code or should we copy paste the whole text file in the code to make calculations faster and space efficient.
Thank you for your help.
I'm personally a fan of the table data type. I would do something like this:
t = readtable('punit.txt','HeaderLines',2,'Delimiter',' '); % read into table
index = t.Lat == -90 & t.Lon==-166; % create a binary indicator as to whether
% each row matches the criteria
my_data = t{index, 3:14}; % extract the data into a matlab array
mean_my_data = mean(my_data, 2); % calculate mean (2 makes it along columns)
You probably already know this, but I would put this code in a file like my_script.m and then call the script from the matlab workspace with my_script.
Matthew's answer is perfectly acceptable. In fact, it's the approach I'd side with. However, if you don't have access to the table interface as it was introduced in R2013b, dlmread may be more suitable for use. Simply skip three lines and use space as the delimiter to read in that matrix into MATLAB.
Once you read in this matrix, search for all rows where the first column has -90 and the second column has -166, index into your matrix and find the mean over each column. Assuming your text file is called data.txt:
data = dlmread('data.txt', ' ', 3, 0);
ind = data(:,1) == -90 & data(:,2) == -166;
extract = data(ind,3:end);
mean_data = mean(extract, 1);
The first line of code reads in the text file as a numerical matrix and skips the first three lines. Spaces are used as the delimiter. Next, we find a Boolean vector which finds all rows where the first column is -90 and simultaneously the second column being -166. Once we find these rows, we subset into the data and extract only the third column and onwards as we don't want to include the latitude and longitude as part of the calculations.
Once we extract this data, we find the averages of each month individually using mean and to find the column-wise averages, use the second parameter with the value of 1, meaning that the averages over the first dimension or the rows is what is sought.
Try Matlab Import Data button Go to Home tab-> in the Variable section-> select Import Data.
Select your text file and get whichever row or column you want to import.
Alternatively, right click name of the file in Current Folder browser and select Import Data. --> The Import Tool opens.
it is possible to create variables also in your Matlab workspace.
It works better than copy pasting manually and less time consuming.
I have a 5x5 matrix
A =
[0 0 0 0 1;
0.36 0 0 0 1;
0 0.25 0 0 1;
0.35 0 0 0 1;
0 0 0.28 0 1];
I want to extract lower triangular elements of the matrix without considering the diagonal elements. Therefore, resulting matrix should be
C = [0.36 0 0.35 0 0.25 0 0 0 0.28 0]
Let me know how I can get this.
You can use matlab tril, e.g.:
index = find(tril(ones(size(A)), -1));
C = A(index);
I'm assuming this is Matlab, based on the format of the matrices.
If you want the elements of the lower triangular portion in a row vector, you can do it with a loop (although I'm sure somebody will have a nifty vectorized approach):
C=[];
for n=1:size(A,1)
C=[C,A(n+1:end,n)'];
end
The output is:
C =
0.36 0.00 0.35 0.00 0.25 0.00 0.00 0.00 0.28 0.00
If instead you want the full 5x5 matrix, you would use the second argument of tril:
C = tril(A,-1);
The output is:
C =
0.00 0.00 0.00 0.00 0.00
0.36 0.00 0.00 0.00 0.00
0.00 0.25 0.00 0.00 0.00
0.35 0.00 0.00 0.00 0.00
0.00 0.00 0.28 0.00 0.00
bsxfun-based approach:
C = A( bsxfun(#gt, (1:size(A,1)).', 1:size(A,2)) ).';
I have pdb (protein data base) file which has thousands of lines.
REMARK 1 PDB file generated by ptraj (set 1000)
ATOM 1 O22 DDM 1 2.800 4.419 20.868 0.00 0.00
ATOM 2 H22 DDM 1 3.427 4.096 20.216 0.00 0.00
ATOM 3 C22 DDM 1 3.351 5.588 21.698 0.00 0.00
ATOM 4 H42 DDM 1 3.456 5.274 22.736 0.00 0.00
ATOM 5 C23 DDM 1 2.530 6.846 21.639 0.00 0.00
ATOM 6 H43 DDM 1 2.347 7.159 20.611 0.00 0.00
ATOM 7 O23 DDM 1 1.313 6.498 22.334 0.00 0.00
ATOM 8 H23 DDM 1 0.903 5.837 21.771 0.00 0.00
ATOM 9 C24 DDM 1 3.073 8.109 22.266 0.00 0.00
ATOM 10 H44 DDM 1 3.139 7.837 23.319 0.00 0.00
ATOM 11 O24 DDM 1 2.218 9.278 22.007 0.00 0.00
ATOM 12 H24 DDM 1 1.278 9.184 22.179 0.00 0.00
ATOM 13 C25 DDM 1 4.494 8.317 21.764 0.00 0.00
ATOM 14 H45 DDM 1 4.391 8.452 20.687 0.00 0.00
'
I want to insert word "TER" every 81 lines in that file whcih contains more than 20,000 lines but ignoring the first line since it is a comment.
I browse through internet, seems SED can do it. But i am lost.
Can anyone guide?
Thanks in advance.
Try this:
sed -i -e '1~81 i\TER' file
I'm partial to awk myself:
awk '{if(FNR%81==0)print "TER"; print}' file
I find this is a lot easier to understand and debug than the sed equivalent. The only magic is that FNR is the line number
You might have to fiddle with the numbers in the if to get it exactly the way you want it.
The more verbose shell commands would be
{
read header
echo "$header"
i=0
while read line; do
echo "$line"
if (( ++i == 81 )); then
echo TER
i=0
fi
done
} < infile > outfile &&
mv outfile infile
What's the best method for benchmarking the performance of my various templates when using Template::Toolkit?
I want something that will break down how much cpu/system time is spent processing each block or template file, exclusive of the time spent processing other templates within. Devel::DProf, for example, is useless for this, since it simply tells me how much time is spent in the various internal methods of the Template module.
It turns out that Googling for template::toolkit profiling yields the best result, an article from November 2005 by Randal Schwartz. I can't copy and paste any of the article here due to copyright, but suffice to say that you simply get his source and use it as a module after template, like so:
use Template;
use My::Template::Context;
And you'll get output like this to STDERR when your script runs:
-- info.html at Thu Nov 13 09:33:26 2008:
cnt clk user sys cuser csys template
1 0 0.06 0.00 0.00 0.00 actions.html
1 0 0.00 0.00 0.00 0.00 banner.html
1 0 0.00 0.00 0.00 0.00 common_javascript.html
1 0 0.01 0.00 0.00 0.00 datetime.html
1 0 0.01 0.00 0.00 0.00 diag.html
3 0 0.02 0.00 0.00 0.00 field_table
1 0 0.00 0.00 0.00 0.00 header.html
1 0 0.01 0.00 0.00 0.00 info.html
1 0 0.01 0.01 0.00 0.00 my_checklists.html
1 0 0.00 0.00 0.00 0.00 my_javascript.html
1 0 0.00 0.00 0.00 0.00 qualifier.html
52 0 0.30 0.00 0.00 0.00 referral_options
1 0 0.01 0.00 0.00 0.00 relationship_block
1 0 0.00 0.00 0.00 0.00 set_bgcolor.html
1 0 0.00 0.00 0.00 0.00 shared_javascript.html
2 0 0.00 0.00 0.00 0.00 table_block
1 0 0.03 0.00 0.00 0.00 ticket.html
1 0 0.08 0.00 0.00 0.00 ticket_actions.html
-- end
Note that blocks as well as separate files are listed.
This is, IMHO, much more useful than the CPAN module Template::Timer.