I want Mathemtica to stop manipulating my polynomials! I mean, I want the output of
Print[3 x + 5 + x^2]
to be just $3x+5+x^2$, not $5+3x+x^2$ as Mathematica returns.
How can I do this?
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2 Answers
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Will
a = -3; Print[Defer[\[FormalA] x + 5 + x^2] /. \[FormalA] -> a]
-3 x + 5 + x^2
work for you?
answered Jul 3, 2014 at 22:23
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$\begingroup$ it may not work for
1or0. but don't know what's OP need. $\endgroup$– Kuba ♦Jul 4, 2014 at 0:05
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What about
Print[HoldForm[3 x + 5 + x^2]]
?
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$\begingroup$ Well, if we have parameters, there will be another problem: commands a=-3; Print[HoldForm[ax-5+x^2]] yield $ax-5+x^2$, not $-3x-5+x^2$. $\endgroup$– BehzadJul 3, 2014 at 22:13
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1$\begingroup$ @Behzad There will always be a problem unless you post full context :) this answer fits the question. You can use
Withto inject in held expressions but I suppose it may still be a problem with sign marks.With[{a = -3}, HoldForm[a x - 5 + x^2]]$\endgroup$– Kuba ♦Jul 3, 2014 at 22:19 -
$\begingroup$ @Kuba Interesting question though, because
fun = 3 x + 5 + x^2; and thenPrint[HoldForm@fun]doesn't work. $\endgroup$– eldoJul 3, 2014 at 22:26 -
$\begingroup$ @eldo With
Setit is already lost so even if you inject it it will be formated :) but withSetDelayedyou can do:ClearAll[fun]; fun := 3 x + 5 + x^2;and thenHoldForm[fun] /. OwnValues@fun$\endgroup$– Kuba ♦Jul 3, 2014 at 22:30 -
$\begingroup$ @kuba Brilliant ! If OP wants this, he could even append a
// Printafter/. OwnValues@fun. $\endgroup$– eldoJul 3, 2014 at 22:44
Defer[]will do what you want? (I guess it will depend on how you want to use the expression.) $\endgroup$With[{a=3}, Print@HoldForm[a x - 5 + x^2]]does work, but I don't know if it's general enough for your use case. $\endgroup$