Comments and Ratings

Thanks Jim!

I made that change for compatibility with Macs. Also, based on your first comment back in October I increased the speed of the code by a factor of 3 in a moderate-sized directory tree.

OOPS, that second part should read:
saSubDirs = dir(strStartDir);
saSubDirs = saSubDirs([saSubDirs.isdir]);

Just to clarify on that last point, keeping a cell array of all directories to process, then using addpath(pathsOut{:},strXorIntAddpathMode) (where pathsOut is a cell array of all paths to add) works well

I am giving this a higher rating now because it is named properly and the new code can handle vectors. Thanks!

The file that I downloaded is called date2julian when it should be called date2doy according to the file information.

I was looking for a function to convert from MATLAB serial date format to a day of year (1-365) and this one does that. It is just that the file name and documentation is misleading witht he mention of Julian dates.

Inside the code, the author uses ACCUMARRAY on the values of the input array. This is a poor choice because it might create a large chunk of memory and slow down greatly.

Here is a code to check this effect. On my computer the worse time is 2.5 s, and unique can accomplish in less than 1 ms.

power=1:64;
time=zeros(length(power),2);

for k=1:length(power)
    
    twoelem=[0 2.^power(k)-1];
    disp(twoelem)
    
    tic
    count_unique(twoelem);
    time(k,1) = toc;
    
    tic
    unique(twoelem);
    time(k,2) = toc;
end
fprintf('worse time = %g s\n', max(time,[],1))
plot(power,time);
ylabel('second');
title('Time for array of two elements')
legend('count unique','unique')

John,
The code is primarily used to count the number of each unique instance within an array, but as a side benefit is slightly faster than the existing unique function (and quite a bit faster for integer-valued arrays). I'll modify the description to make this more obvious.

Thanks for your comments.

You can avoid the first bug I mentioned above by adding the following at line 59:
currDir = currDir([currDir.isdir]);

Oh, and I just checked in genpath, and see that IT uses recursive calls to 'dir'. Therefore my second suggestion doesn't actually avoid these multiple calls!

Be aware: you are using assert function. This is not available in R14 or previous!
Moreover I am not sure if assert exit the function...

@Author: the idea of an ignore option is good.
Good would be if you could also directly pass through ignore filter like "all directories starting wih "@" or "#"". At the best would be generic wildcard expressions.
Small missing point:Your implementation does not allow to use addpath intrinsec option like -BEGIN and -END.
You removed some features from original Matlab GENPATH which make your version not optimized. (private and @ not ignored by default; your loop run also over all files!)
------
@Jesse: this can be done with a small correction in the code:
if ~any(strcmp(currDir(m).name,{'.','..',ignore{:}})) && currDir(m).isdir && ~strncmp(currDir(m).name,'@',1) && ~any(strcmp(currDir(m).name,{'private','.',,'..')) ...
(see also original GENPATH)

Thanks for the tip about anonymous functions, I do see how they work now.

However, you are wrong that this is EXACTLY what the anonymous functions do. To minimize and objective function in general like this, you will either need separate m-files for your various objective functions, or will have to re-create them as anonymous functions every time you use them. There are TWO function calls here: 1) to the actual MATLAB function which you are minimizing, and 2) to the objective function that will evaluate the target function's output and provide a single value for optimization.

I encourage anyone embedding optimization in larger programs, or working with optimization that involves multiple target functions and different objective functions to give this a try.

This function is simpler than anonymous functions, and though duplicate in some fashions, not necessarily useless.

As far as the "ugly" line, that is how function handles are defined using variable inputs. Sometimes eval is necessary, even though it is not the most optimizable MATLAB facility.

I corrected my mistake about the version numbering, thank you for that.

It IS what anonymous functions do for us. And, they will do it far better and more easily than this submission. Plus, they will surely be more efficient.

The only reason I did not say anything immediately when this appeared is this submission is claimed to work on older releases of Matlab, and anonymous functions were introduced only in version 7. Since that ability is untested by the author and I am unable to test it, I won't say anything more, nor should I provide a rating.

Genpath is unable to ignore directories, which is a key feature for certain uses (like source code repositories). That's the real utility of this function.

I did not give this submission a good rating for the following reasons:

1) This routine basically returns the day of the year, not a Julian day. The term Julian day should be reserved for the astronomical definition of days since noon Universal Time (UT) Monday, January 1, 4713 BC. So the name of the function and the description should be something like datenum2doy.m, or the like. Descriptions like "... Julian days since the start of the year ... " are ambiguous and should be removed.

2) This routine takes a datenum type of variable as an input, but the variable name used by the author is date, and date is an existing MATLAB function name. This may be confusing to users. The name of the input date variable should be changed.

3) The functionality provided by this routine is fairly simple. For example, the following few MATLAB lines essentially do the same thing for the day-of-year calculation and are just as fast:

function doy = datenum2doy(dn)
dv = datevec(dn);
dv(:,2:end) = 0;
doy = dn - datenum(dv);
end

In summary, I gave this submission a low score because of the simple functionality provided and the misuse of the Julian day terminology. The author did comment his code, which is why I gave it a 2 instead of a 1. (you should always give people who comment their code *some* reward).

James Tursa