Re: How to detect 'bad' characters in expressions in the notebook?

*To*: mathgroup at smc.vnet.net*Subject*: [mg113361] Re: How to detect 'bad' characters in expressions in the notebook?*From*: Joseph Gwinn <joegwinn at comcast.net>*Date*: Mon, 25 Oct 2010 06:41:08 -0400 (EDT)*References*: <ia10fv$otk$1@smc.vnet.net>

In article <ia10fv$otk$1 at smc.vnet.net>, "Nasser M. Abbasi" <nma at 12000.org> wrote: > Experts; > > I copied a Mathematica expression from a PDF file to a Mathematica > notebook (by using the mouse, selected the expressions and pasted it > into a new cell in the notebook). > > The expression looked fine, nothing that I can see wrong with it. But > when I execute it, Mathematica complained with an error message that did > not make any sense given what I have on the screen. > > I knew that there was some problem with the copy, because when I typed > the same exact command below it, it worked with no errors. > > But looking at the screen, both what I copied and what I typed, are > exactly the same. Absolutely exactly the same expressions looked the > same on the screen as you can see yourself by looking at the screen > shot, link below. > > But when I converted the commands to inputForm to compare the copied > command with the I typed, I saw the difference. > > In the PDF copied command, it had > > PlotRange->{} > > The arrow was the problem. > > For some reason, it remained of some encoding which did not match > Mathematica's own -> that one enters by typing dash followed by > which > then Mathematica converts automatically to a nice solid one glyph ->. > > Here is an image showing the problem > http://12000.org/tmp/hidden_stuff/image.png > > And here is the notebook > http://12000.org/tmp/hidden_stuff/hidden.nb > > So, my question: was there a way I could have asked Mathematica to > highlight such characters as being ones which it did not recognize? > > This would have saved much time. > > I have had such problems before, where what I look at in the notebook, > is not what I think it is. The above is an example. > > I guess my lesson for today: next time I copy something from a PDF file > or other source to the notebook, I better examine each character in > inputForm before using it even if it did look OK on the screen. > > Sounds like so much fun. Could be a while. In the mean time, a faster approach would be to paste the quotation into a text editor like UltraEdit32 (Windows) or BBEdit (Mac or Windows), tell it to use the Latin 1 encodings only, and to zap gremlins, and then copy the surviving text and paste it into Mathematica. This is efficient for large amounts of text, but for a few lines manual retyping is probably faster. Joe Gwinn