tex1() seems to return all strings as follow:
tex1(hello);
{\it hello}
tex1("hello");
\mbox{ hello }
What variable must one use to change this handling via texput? e.g. if I would just like it to print strings literally? I'm using other Maxima commands (like printf and concat to produce strings that are then passed to tex1, and occasionally the default handling is causing issues.
I tried texput(""", ...) and texput("''", ...); the first wasn't accepted, the 2nd was, but did not change the output. I really have no clue for the non-quoted strings.
Let's be careful to distinguish symbols from strings. When you enter tex1(hello) then hello is a symbol, and when you enter tex1("hello") then "hello" is a string. Symbols are essentially names for items in a lookup table, which can store additional info (symbol properties) for each. Strings on the other hand are just (from Maxima's point of view) just a sequence of characters.
Anyway changing the output for all symbols or all strings is unfortunately not possible via texput. But with a one-line Lisp function, one can accomplish it. Try this: for symbols,
:lisp (defun tex-stripdollar (sym) (maybe-invert-string-case (symbol-name (stripdollar sym))))
and for strings,
:lisp (defun tex-string (str) str)
These are going to change some existing outputs, so you'll want to try it and see if it works for you.
Related
I'm trying to automate some output using printf but I'm struggling to find a way to pass to it the list of arguments expr_1, ..., expr_n in
printf (dest, string, expr_1, ..., expr_n)
I thought of using something like Javascript's spread operator but I'm not even sure I should need it.
For instace, say I have a list of strings to be output
a:["foo","bar","foobar"];
a string of appropriate format descriptors, say
s: "~a ~a ~a ~%";
and an output stream, say os. How can I invoke printf using these things in such a way that the result will be the same as writing
printf(os,s,a[1],a[2],a[3]);
Then I could generalize it to output lists of variable size.
Any suggestions?
Thanks.
EDIT:
I just learned about apply and, using the conditions I posed in my OP, the following seems to work wonderfully:
apply(printf,append([os,s],a));
Maxima printf implements most or maybe all of the formatting operators from Common Lisp FORMAT, which are quite extensive; see: http://www.lispworks.com/documentation/HyperSpec/Body/22_c.htm See also ? printf in Maxima to get an abbreviated list of formatting operators.
In particular for a list you can do something like:
printf (os, "my list: ~{~a~^, ~}~%", a);
to get the elements of a separated by ,. Here "~{...~}" tells printf to expect a list, and ~a is how to format each element, ~^ means omit the inter-element stuff after the last element, and , means put that between elements. Of course , could be anything.
There are many variations on that; if that's not what you're looking for, maybe I can help you find it.
I am writing an program in which I am dealing with strings in the form, e.g., of "\001SOURCE\001". That is, the strings contained alphanumeric text with an ASCII character of value 1 at each end. I am trying to write a function to match strings like these. I have tried a match like this:
handle(<<1,"SOURCE",1>>) -> ok.
But the match does not succeed. I have tried a few variations on this theme, but all have failed.
Is there a way to match a string that contains mostly alphanumeric text, with the exception of a non-alpha character at each end?
You can also do the following
[1] ++ "SOURCE" ++ [1] == "\001SOURCE\001".
Or convert to binary using list_to_binary and pattern match as
<<1,"SOURCE",1>> == <<"\001SOURCE\001">>.
Strings are syntactic sugar for lists. Lists are a type and binaries are a different type, so your match isn't working out because you're trying to match a list against a binary (same problem if you tried to match {1, "STRING", 1} to it, tuples aren't lists).
Remembering that strings are lists, we have a few options:
handle([1,83,84,82,73,78,71,1]) -> ok.
This will work just fine. Another, more readable (but uglier, sort of) way is to use character literals:
handle([1, $S,$T,$R,$I,$N,$G, 1]) -> ok.
Yet another way would be to strip the non-character values, and then pass that on to a handler:
handle(String) -> dispatch(string:strip(String, both, 1)).
dispatch("STRING") -> do_stuff();
dispatch("OTHER") -> do_other_stuff().
And, if at all possible, the best case is if you just stop using strings for text values entirely (if that's feasible) and process binaries directly instead. The syntax of binaries is much friendlier, they take up way fewer resources, and quite a few binary operations are significantly more efficient than their string/list counterparts. But that doesn't fit every case! (But its awesome when dealing with sockets...)
I'm using Racket Scheme. I have a string defined and I'm attempting to parse it.
I initially have
(define expression (open-input-string "(expression here)"))
And now I'm attempting to iterate over all the characters using the scheme read function. I'm new to scheme though and I'm not quite sure how to properly loop them.
Essentially I need to loop all
read-char expression
Thanks
You don't want plain read for something like this. It is built to read Scheme/Racket syntax, not arbitrary data. Instead, you probably want string->list, which splits a string into a list of characters.
(string->list "(expression here)")
; => '(#\( #\e #\x #\p #\r #\e #\s #\s #\i #\o #\n #\space #\h #\e #\r #\e #\))
Perhaps you don't want to read the whole string at once, though? There does exist a read-char function, as you include in your post. There are lots of ways to loop in Racket. You can use recursion, or you can use Racket's plethora of for loop forms.
Still, if you have an input port and you just want to loop over all the characters, well, there's an easy way to do that, too! You can use the handy in-input-port-chars sequence with for loops like this:
(define expression (open-input-string "(expression here)"))
(for ([c (in-input-port-chars expression)])
(display c))
; => (expression here)
Trying to generate a list through comprehension and at some point I start seeing strange character strings. Unable to explain their presence at this point (guessing the escape chars to be ASCII codes - but why?):
45> [[round(math:pow(X,2))] ++ [Y]|| X <- lists:seq(5,10), Y <- lists:seq(5,10)].
[[25,5],
[25,6],
[25,7],
[25,8],
[25,9],
[25,10],
[36,5],
[36,6],
[36,7],
"$\b","$\t","$\n",
[49,5],
[49,6],
[49,7],
"1\b","1\t","1\n",
[64,5],
[64,6],
[64,7],
"#\b","#\t","#\n",
[81,5],
[81,6],
[81,7],
"Q\b",
[...]|...]
In Erlang all strings are just list of small integers (like chars in C). And shell to help you out a little tries to interpret any list as printable string. So what you get are numbers, they are just printed in a way you would not expect.
If you would like to change this behaviour you can look at this answer.
I need to remove all \text generated by TeXForm in Mathematica.
What I am doing now is this:
MyTeXForm[a_]:=StringReplace[ToString[TeXForm[a]], "\\text" -> ""]
But the result keeps the braces, for example:
for a=fx,
the result of TeXForm[a] is \text{fx}
the result of MyTeXForm[a] is {fx}
But what I would like is it to be just fx
You should be able to use string patterns. Based on http://reference.wolfram.com/mathematica/tutorial/StringPatterns.html, something like the following should work:
MyTeXForm[a_]:=StringReplace[ToString[TeXForm[a]], "\\text{"~~s___~~"}"->s]
I don't have Mathematica handy right now, but this should say 'Match "\text{" followed by zero or more characters that are stored in the variable s, followed by "}", then replace all of that with whatever is stored in s.'
UPDATE:
The above works in the simplest case of there being a single "\text{...}" element, but the pattern s___ is greedy, so on input a+bb+xx+y, which Mathematica's TeXForm renders as "a+\text{bb}+\text{xx}+y", it matches everything between the first "\text{" and last "}" --- so, "bb}+\text{xx" --- leading to the output
In[1]:= MyTeXForm[a+bb+xx+y]
Out[1]= a+bb}+\text{xx+y
A fix for this is to wrap the pattern with Shortest[], leading to a second definition
In[2]:= MyTeXForm2[a_] := StringReplace[
ToString[TeXForm[a]],
Shortest["\\text{" ~~ s___ ~~ "}"] -> s
]
which yields the output
In[3]:= MyTeXForm2[a+bb+xx+y]
Out[3]= a+bb+xx+y
as desired.
Unfortunately this still won't work when the text itself contains a closing brace. For example, the input f["a}b","c}d"] (for some reason...) would give
In[4]:= MyTeXForm2[f["a}b","c}d"]]
Out[4]= f(a$\$b},c$\$d})
instead of "f(a$\}$b,c$\}$d)", which would be the proper processing of the TeXForm output "f(\text{a$\}$b},\text{c$\}$d})".
This is what I did (works fine for me):
MyTeXForm[a_] := ToString[ToExpression[StringReplace[ToString[TeXForm[a]], "\\text" -> ""]][[1]]]
This is a really late reply, but I just came up against the same issue and discovered a simple solution. Put a space between the variables in the Mathematica expression that you wish to convert using TexForm.
For the original poster's example, the following code works great:
a=f x
TeXForm[a]
The output is as desired: f x
Since LaTeX will ignore that space in math mode, things will format correctly.
(As an aside, I was having the same issue with subscripted expressions that have two side-by-side variables in the subscript. Inserting a space between them solved the issue.)