convert(file.ext,string)
gives a different result depending on the Maple's current version in use. In Maple v14 gives "file.ext" but in Maple v15 gives "file . ext" (with spaces before and after the point). Can anybody explain me this? Thanks in advance.
Yes, there is a difference, but more important is that the approach to form the string in this manner is misguided.
There are no special (delayed) evaluation rules for the command convert, and what that routine sees as the first argument here is the result of the (noncommutating) multiplication of the name file with the name ext. And so that's not really a great way to concatenate to a string, because it's purpose is not to first carefully concatenate.
There are alternatives. You could concatenate to a single name, and then convert that to a string, or you could concatenate directly to a string (for which the command convert/string is not best).
# I'm supposing that one does want the name`file` assigned
file:=myproject:
# Now suppose that one wants the result "myproject.for"
ext:=`for`:
convert(file.ext,string); # whoops
"myproject . `for`"
cat(file,".",ext); # produces the name `myproject.for`
myproject.for
convert(%,string);
"myproject.for"
sprintf("%a.%s",file,ext);
"myproject.for"
Related
I have different commands my program is reading in (i.e., print, count, min, max, etc.). These words can also include a number at the end of them (i.e., print3, count1, min2, max6, etc.). I'm trying to figure out a way to extract the command and the number so that I can use both in my code.
I'm struggling to figure out a way to find the last element in the string in order to extract it, in Smalltalk.
You didn't told which incarnation of Smalltalk you use, so I will explain what I would do in Pharo, that is the one I'm familiar with.
As someone that is playing with Pharo a few months at most, I can tell you the sheer amount of classes and methods available can feel overpowering at first, but the environment actually makes easy to find things. For example, when you know the exact input and output you want, but doesn't know if a method already exists somewhere, or its name, the Finder actually allow you to search by giving a example. You can open it in the world menu, as shown bellow:
By default it seeks selectors (method names) matching your input terms:
But this default is not what we need right now, so you must change the option in the upper right box to "Examples", and type in the search field a example of the input, followed by the output you want, both separated by a ".". The input example I used was the string 'max6', followed by the desired result, the number 6. Pharo then gives me a list of methods that match that:
To get what would return us the text part, you can make a new search, changing the example output from number 6 to the string 'max':
Fortunately there is several built-in methods matching the description of your problem.
There are more elegant ways, I suppose, but you can make use of the fact that String>>#asNumber only parses the part it can recognize. So you can do
'print31' reversed asNumber asString reversed asNumber
to give you 31. That only works if there actually is a number at the end.
This is one of those cases where we can presume the input data has a specific form, ie, the only numbers appear at the end of the string, and you want all those numbers. In that case it's not too hard to do, really, just:
numText := 'Kalahari78' select: [ :each | each isDigit ].
num := numText asInteger. "78"
To get the rest of the string without the digits, you can just use this:
'Kalahari78' withoutTrailingDigits. "Kalahari"6
As some of the Pharo "OGs" pointed out, you can take a look at the String class (just type CMD-Return, type in String, hit Return) and you will find an amazing number of methods for all kinds of things. Usually you can get some ideas from those. But then there are times when you really just need an answer!
I have to extract the onset times for a fMRI experiment. I have a nested output called "ResOut", which contains different matrices. One of these is called "cond", and I need the 4th element of it [1,2,3,4]. But I need to know its onset time just when the items in "pict" matrix (inside ResOut file) have a name that ends with "*v.JPG".
Here's the part of the code that I wrote (but it's not working):
for i=1:length(ResOut);
if ResOut(i).cond(4)==1 && ResOut(i).pict== endsWith(*"v.JPG")
What's wrong? Can you halp me to fix it out?
Thank you in advance,
Adriano
It's generally helpful to start with unfamiliar functions by reading their documentation to understand what inputs they are expecting. Per the documentation for endsWith, it expects two inputs: the input text and the pattern to match. In your example, you are only passing it one (incorrectly formatted) string input, so it's going to error out.
To fix this, call the function properly. For example:
filepath = ["./Some Path/mazeltov.jpg"; "~/Some Path/myfile.jpg"];
test = endsWith(filepath, 'v.jpg')
Returns:
test =
2×1 logical array
1
0
Or, more specifically to your code snippet:
endsWith(ResOut(i).pict, 'v.JPG')
Note that there is an optional third input, 'IgnoreCase', which you can pass as a boolean true/false to control whether or not the matching ignores case.
I have to write a MATLAB function with the following description:
function counts = letterStatistics(filename, allowedChar, N)
This function is supposed to open a text file specified by filename and read its entire contents. The contents will be parsed such that any character that isn’t in allowedChar is removed. Finally it will return a count of all N-symbol combinations in the parsed text. This function should be stored in a file name “letterStatistics.m” and I made a list of some commands and things of how the function should be organized according to my professors' lecture notes:
Begin the function by setting the default value of N to 1 in case:
a. The user specifies a 0 or negative value of N.
b. The user doesn’t pass the argument N into the function, i.e., counts = letterStatistics(filename, allowedChar)
Using the fopen function, open the file filename for reading in text mode.
Using the function fscanf, read in all the contents of the opened file into a string variable.
I know there exists a MATLAB function to turn all letters in a string to lower case. Since my analysis will disregard case, I have to use this function on the string of text.
Parse this string variable as follows (use logical indexing or regular expressions – do not use for loops):
a. We want to remove all newline characters without this occurring:
e.g.
In my younger and more vulnerable years my father gave me some advice that I've been turning over in my mind ever since.
In my younger and more vulnerableyears my father gave me some advicethat I’ve been turning over in my mindever since.
Replace all newline characters (special character \n) with a single space: ' '.
b. We will treat hyphenated words as two separate words, hence do the same for hyphens '-'.
c. Remove any character that is not in allowedChar. Hint: use regexprep with an empty string '' as an argument for replace.
d. Any sequence of two or more blank spaces should be replaced by a single blank space.
Use the provided permsRep function, to create a matrix of all possible N-symbol combinations of the symbols in allowedChar.
Using the strfind function, count all the N-symbol combinations in the parsed text into an array counts. Do not loop through each character in your parsed text as you would in a C program.
Close the opened file using fclose.
HERE IS MY QUESTION: so as you can see i have made this list of what the function is, what it should do, and using which commands (fclose etc.). the trouble is that I'm aware that closing the file involves use of 'fclose' but other than that I'm not sure how to execute #8. Same goes for the whole function creation. I have a vague idea of how to create a function using what commands but I'm unable to produce the actual code.. how should I begin? Any guidance/hints would seriously be appreciated because I'm having programmers' block and am unable to start!
I think that you are new to matlab, so the documentation may be complicated. The root of the problem is the basic understanding of file I/O (input/output) I guess. So the thing is that when you open the file using fopen, matlab returns a pointer to that file, which is generally called a file ID. When you call fclose you want matlab to understand that you want to close that file. So what you have to do is to use fclose with the correct file ID.
fid = open('test.txt');
fprintf(fid,'This is a test.\n');
fclose(fid);
fid = 0; % Optional, this will make it clear that the file is not open,
% but it is not necessary since matlab will send a not open message anyway
Regarding the function creation the syntax is something like this:
function out = myFcn(x,y)
z = x*y;
fprintf('z=%.0f\n',z); % Print value of z in the command window
out = z>0;
This is a function that checks if two numbers are positive and returns true they are. If not it returns false. This may not be the best way to do this test, but it works as example I guess.
Please comment if this is not what you want to know.
I used max(list.files(path, "my_files_v")) to read in the latest my_files_v version.
The directory had files of:
my_files_v1, my_files_v2, ... my_files_v9
My code seemed to work perfectly fine as the script read in always the my_file_v with the highest version until I came to version _v10. From that point onwards max(list.files(..)) always detected _v9 as the max and therefore skipped _v10 and _v11 etc.
One solution would be to extract the version number from the string using substr or something like that but is there a better way of doing that? If not, does anyone know how to extract that pattern from a string as I am very poor regarding that
You could use:
max(as.integer(gsub('my_files_v', '', list.files(path, "my_files_v")))
assuming your files do not have extensions like you've shown. However, so they sort properly in my file browsers, I usually name files with zero padding. In R you can do that with sprintf:
sprintf('%03d', 1:10)
For what its worth, to extract the number portion of the file name you can use regular expressions and grouping:
gsub('my_files_v([0-9]+)\\.Rdata', '\\1', list.files(path, 'my_files_v'))
Does any one know how to generate the possible misspelling ?
Example : unemployment
- uemployment
- onemploymnet
-- etc.
If you just want to generate a list of possible misspellings, you might try a tool like this one. Otherwise, in SAS you might be able to use a function like COMPGED to compute a measure of the similarity between the string someone entered, and the one you wanted them to type. If the two are "close enough" by your standard, replace their text with the one you wanted.
Here is an example that computes the Generalized Edit Distance between "unemployment" and a variety of plausible mispellings.
data misspell;
input misspell $16.;
length misspell string $16.;
retain string "unemployment";
GED=compged(misspell, string,'iL');
datalines;
nemployment
uemployment
unmployment
uneployment
unemloyment
unempoyment
unemplyment
unemploment
unemployent
unemploymnt
unemploymet
unemploymen
unemploymenyt
unemploymenty
unemploymenht
unemploymenth
unemploymengt
unemploymentg
unemploymenft
unemploymentf
blahblah
;
proc print data=misspell label;
label GED='Generalized Edit Distance';
var misspell string GED;
run;
Essentially you are trying to develop a list of text strings based on some rule of thumb, such as one letter is missing from the word, that a letter is misplaced into the wrong spot, that one letter was mistyped, etc. The problem is that these rules have to be explicitly defined before you can write the code, in SAS or any other language (this is what Chris was referring to). If your requirement is reduced to this one-wrong-letter scenario then this might be managable; otherwise, the commenters are correct and you can easily create massive lists of incorrect spellings (after all, all combinations except "unemployment" constitute a misspelling of that word).
Having said that, there are many ways in SAS to accomplish this text manipulation (rx functions, some combination of other text-string functions, macros); however, there are probably better ways to accomplish this. I would suggest an external Perl process to generate a text file that can be read into SAS, but other programmers might have better alternatives.
If you are looking for a general spell checker, SAS does have proc spell.
It will take some tweaking to get it working for your situation; it's very old and clunky. It doesn't work well in this case, but you may have better results if you try and use another dictionary? A Google search will show other examples.
filename name temp lrecl=256;
options caps;
data _null_;
file name;
informat name $256.;
input name &;
put name;
cards;
uemployment
onemploymnet
;
proc spell in=name
dictionary=SASHELP.BASE.NAMES
suggest;
run;
options nocaps;