I have some complicated array of structures and I want to write it into CSV file. So I need "variable to string" conversion.
Beckhoff as always doesn't care about documentation and their INT_TO_STRING function doesn't work (UNEXPECTED INT_TO_STRING TOKEN when I try to write INT_TO_STRING(20) ).
Moreover their string functions works correctly with only 255 chars.
So I need one of following:
working functions or function blocks or library which allows to convert different types to string
something like sprintf without limitations
some functions to convert between number and ascii char (0x55 is letter 'U') in both directions.
btw. Beckhoff gives us some weird CSV example code, but without data conversion (array has already strings in cells).
Thanks in advance!
I tried to use:
INT_TO_STRING() BYTE_TO_STRING() WHATEVER_TO_STRING()
but it is not working. And there is no clue how many arguments it should have or anything. There is no documentation in Beckhoff information System.
Related
I have a question regarding the interpretation of a string as bytes
Within python, I have the situation that one variable contains e.g. this value
"bytearray(b'\x13\x02US')"
this is unfortunately due to the behavior of a module I am using. My question is, how could i get this string into bytes?
I have tried stripping away the "bytearray(b'" and the "')" at the end, and use .encode() as a function, but the result then is:
b'\\x13\\x02US'
Which clearly escapes the \ in order to prevent the interpretation as bytes.
How could i get this converted into
b'\x13\x02US'
instead though?
Thank you very much!
You could use .decode().replace('\\', '\'), this way it replaces the double slashes with single ones. Either attache it after your .encode() function or do it on your string seperately.
How can I prevent MATLAB Coder to generate variable size code for a simple number insertion into a string?
for i=1:4
name=sprintf('Data%d.bin',int8(i));
stuff(name);
end
In the generated C code it uses a lot of functions like emxutil to determine the size of the generated string for sprtintf.
I just want to say that i is only one digit. How can I do that?!
The followings also do not work
name=['Data',char(i),'.bin'];
Using the following also gives an error for generating code that LHS is fixed sized but RHS is varying:
coder.varsize('name',[1,14],[0,0])
I just tested the following again. It works well and also can be used for more digits, and it does not use var size stuff.
name=['Data',int2str(i),'.bin'];
Also, these can be used if we are sure that i is one digit:
['Data' char(48+i) '.bin']
['Data' char('0'+i) '.bin']
I have a string with commas in between. How should I convert this string into an integer. I tried using
x?number
but that gives me the following error
Exceptionfreemarker.core.NonNumericalException
e.g. The string is "453,000". I need to convert this to 453000.
Is there any other way of doing this?
There's no function built in for parsing numbers with national formats. ?number only deals with computer format, because when numbers are transferred as strings (which should be already rare), that's what used to be used. So in principle x should be already a number when it gets to FreeMarker, or at least it should use computer format. If that's not possible, you will need a custom function (or method) for that.
Let's say I have this variable:
st='MI'
and I want to convert it to:
st=''' 'MI' '''
to use it in a SQL command.
What's the best way to accomplish this?
Thanks in advance!
Tripleor single quoting are just ways of typing strings into source code files.
Once your program is running, your string is already a string, and there is no need to make any cnversion to use it as a parameter to a SQL driver function call.
What you may want i to have a string with an SQL statement that itself contains various (single or double) quote characters. If that is typed in your Python source code file, you can type the triple-quote straight. If you are getting these SQL statements from elsewhere, they are already strings, as I said above.
Now, there are a few instances in which you have a string in a running Python program, or a Python interactive session, that you would like printed, so that you can paste it directly in source code. For these cases you can try the "unicode_escape" codec (and recode it to text so that it does not double your backslashes:
In [56]: print("\n".encode("unicode_escape").decode("utf-8"))
\n
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.