Re: MatrixForm odd behaviour
- To: mathgroup at smc.vnet.net
- Subject: [mg124509] Re: MatrixForm odd behaviour
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Sun, 22 Jan 2012 07:22:14 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <201201211021.FAA10265@smc.vnet.net>
- Reply-to: drmajorbob at yahoo.com
> And, since this sets the display on a global > basis rather than an expression by expression basis, there is no > need to change the expression to control the display. > Consequently, the issue with MatrixForm is eliminated. And, consequently, viewing matrices of anything but trivial size becomes hopeless. Bobby On Sat, 21 Jan 2012 04:21:08 -0600, Bill Rowe <readnews at sbcglobal.net> wrote: > On 1/19/12 at 5:08 AM, roby.nowak at gmail.com (roby) wrote: > >> As a similar Question is discussed on the group now. > >> The following issue: > >> When entering e.g.: Dot[MatrixForm[{{1, 0}, {0, 2}}], >> MatrixForm[{{1, 0}, {0, 2}}]] Mathematica does not evaluate the Dot >> operation and displays the two unchanged input matrices seperated by >> a "Dot" each respectively wrapped by MatrixForm, so far so good (or >> perhaps not so good). > >> other funny things to try: TraditionalForm[2] * TraditionalForm[2] >> or: Times[TraditionalForm[2], TraditionalForm[2]] > > The purpose of MatrixForm, TraditionalForm etc is to control the > display of an individual expression. This is accomplished in > Mathematica by changing the Head of an expression. That is: > > In[6]:= a = MatrixForm[b = RandomReal[1, {5, 5}]]; > > In[7]:= Head /@ {a, b} > > Out[7]= {MatrixForm,List} > > In[8]:= MatrixQ /@ {a, b} > > Out[8]= {False,True} > > So, since Mathematica sees the output of MatrixForm as not a > matrix it should be no surprise Mathematica won't evaluate > MatrixForm[m].MatrixForm[m]. > > The simple way to have matrices and other expressions display > the way you see in text books is to set your preferences for > output cells to use TraditionalForm. Once this is done, all > matrices display nicely with no further effort on your part or > use of MatrixForm. And, since this sets the display on a global > basis rather than an expression by expression basis, there is no > need to change the expression to control the display. > Consequently, the issue with MatrixForm is eliminated. > > -- DrMajorBob at yahoo.com
- References:
- Re: MatrixForm odd behaviour
- From: Bill Rowe <readnews@sbcglobal.net>
- Re: MatrixForm odd behaviour