Re: Mathematica frustrations...
- To: firstname.lastname@example.org
- Subject: [mg11168] Re: Mathematica frustrations...
- From: carlos@mars.Colorado.EDU (Carlos A. Felippa)
- Date: Wed, 25 Feb 1998 03:31:42 -0500
- Organization: University of Colorado, Boulder
- References: <email@example.com>
In article <firstname.lastname@example.org> email@example.com writes: >I have recently started learning Mathematica. I'm trying to use it for >some data analysis and plotting, but so far I'm not having much luck. >There are a few specific things that are troubling me, and I'd >really appreciate hearing any advice or suggestions to help me work >around these problems. > >One "feature" I find extremely frustrating is the numbering and >evaluation order of equations in notebooks. When I edit >something early in a notebook, I would like Mathematica to re- >evaluate the rest of the notebook, and always perform the >notebook evaluation in a straight top-to-bottom order. Is there any >way to set an option to get it to behave that way? For things >like "%" references to previous results, having the definition of >"previous" depend on what you edited last seems crazy. I guess I >prefer the Mathcad way, in which evaluation is always in a well-defined >order determined by page layout. > The use of % is a legacy from the original In-Out days of interactive command languages like Basic or Unix. It makes no sense for a Notebook front end. Notebooks are best organized in a procedural style, as collections of modules. What is still lacking in Mathematica is the ability to compile modules and complete cells to machine language and to form a relocatable object library that can be loaded and executed at high speed. This will have to wait until (1) a typing system is introduced, and (2) all module symbols are made local by default and placed in dynamic stacks. In fact it might be useful to get rid altogether of the In[ ] and Out[ ] that still clutter cell boundaries since the numbers that appear therein serve no useful purpose. The symbol % could be reserved for some other purpose such as inline comment marker, or some kind of division. >Another problem is that Mathematica seems to reset plot >parameters at random, particularly after erroneous edits. I am using >the MultipleListPlot and ListPlot functions to create graphs. >After I get the graph sized how I like it (with the mouse), I will >sometimes try changing a few parameters in the graph. If I make >a typo and Mathematica can't understand the command, my graph will jump >to some random different size once I get the error fixed. > No only plot parameters but also output cell formatting & display parameters are often (but not always) forgotten after errors. That could be fixed in some future version. But the best solution would be to permit the input cell to specify those parameters, for example Print[expr//MatrixForm, Background->Yellow,Width->300 TruePt, Font->TimesItalics, TextColor->Red,FontSize->12 Pt]. This guarantees repeatability. >Finally, I'm about to give up on getting reasonable Legends on my plots. In my experience the best way to get legends and labels is to display textstrings as plot objects. Their position can be offset from that of other graphical objects. Precise plot sizing, however, remains elusive because no absolute size specs are available for many objects. That may be contrasted with say TeX, which has a nice two-tier <dim> system: pt, which is affected by magnification, and truept which is not. >Does the PlotLegend option work for MultipleListPlot? Sometimes it >will show a Legend for me, and sometimes it won't. > >FYI, I'm using Mathematica 3.0 on Linux. > >-Brett > >