A Bug / Feature
- To: mathgroup@smc.vnet.net
- Subject: [mg12521] A Bug / Feature
- From: Ersek_Ted%PAX1A@mr.nawcad.navy.mil
- Date: Sat, 23 May 1998 18:10:50 -0400
I don't know if this is a bug or a feature, but I don't like what I get
for {Head[expr], Head[%n]} in the lines below!
In[1]:=
m1=MatrixForm[{{1,2},{3,4}}]
Out[1]//MatrixForm=
(* output deleted *)
In[2]:=
{Head[m1],Head[%1]}
Out[2]=
{MatrixForm, List}
In[3]:=
m2=TableForm[{{1,2},{3,4}}]
Out[3]//TableForm=
(* output deleted *)
In[4]:=
{Head[m2],Head[%3]}
Out[4]=
{TableForm,List}
In[5]:=
m3=TraditionalForm[{{1,2},{3,4}}]
Out[5]//TraditionalForm=
(* output deleted *)
In[6]:=
{Head[m3],Head[%5]}
Out[6]=
{TraditionalForm,List}
In[7]:=
m4=StandardForm[{{1,2},{3,4}}]
Out[7]//StandardForm=
{{1,2},{3,4}}
In[8]:=
{Head[m4],Head[%7]}
Out[8]=
{StandardForm,List}
In[9]:=
num=N[Pi];
In[10]:=
x1=NumberForm[num]
Out[10]//NumberForm=
"3.14159"
In[11]:=
{Head[x1],Head[%10]}
Out[11]=
{NumberForm,Real}
In[12]:=
x2=InputForm[num]
Out[12]//InputForm=
3.141592653589793
In[13]:=
{Head[x2],Head[%12]}
Out[13]=
{InputForm,Real}
_____________________________
If you do the following:
In[1]:=
m1=MatrixForm[{{1,2},{3,4}}]
Out[1]//MatrixForm=
(* output deleted *)
Then you can do;
( In[2]:= Inverse[%1] )
because (%1) has the head List.
But you can't do;
( In[2]:= Inverse[m1] )
because (m1) has the head MatrixForm.
Shouldn't they both have the same head? Makes no sense to me.
Ted Ersek