3

I am trying to write this matrix

enter image description here

But this matrix is awful aesthetically. The middle matrix is tall, the other two are short. I want to make all 3 matrixes the same height.

This is my Latex code:

\tt \color{Black}
\begin{bmatrix}
1 & -1 & -1\\
0 & 13 & -10\\
0 & 7 & \phantom{-} 17 
\end{bmatrix}

\begin{bmatrix}
I_{1}\\
I_{2}\\
I_{3}
\end{bmatrix}

=

\begin{bmatrix}
\phantom{-}0\\
\phantom{-}4\\
-3
\end{bmatrix}

But this is my problem. I am using macOS Pages that have limited Latex support. This is what apple has to say about it.

Unfortunately this solution is not working.

Is there a way to make everything the same height?

thanks

2 Answers 2

5

I looked at the supported commands and it says that \color is supported. This allows one to cheat by putting a white, i.e. invisible, dot on top of the symbols.

\documentclass{article}
\usepackage{amsmath}
\usepackage{color}
\begin{document}
\[
\begin{bmatrix}
\color{white}\dot{\color{black}1} & -1 & -1\phantom{0}\\
\color{white}\dot{\color{black}0} & 13 & -10\\
\color{white}\dot{\color{black}0} & \phantom{-}7 & \phantom{-} 17 
\end{bmatrix}
%
\begin{bmatrix}
I_{1}\\
I_{2}\\
I_{3}
\end{bmatrix}
%
=
%
\begin{bmatrix}
\phantom{-}\color{white}\dot{\color{black}0}\\
\phantom{-}\color{white}\dot{\color{black}4}\\
-\color{white}\dot{\color{black}3}
\end{bmatrix}
\]
\end{document}

I Just checked myself, if you remove the %, i.e. insert

\[
\begin{bmatrix}
\color{white}\dot{\color{black}1} & -1 & -1\phantom{0}\\
\color{white}\dot{\color{black}0} & 13 & -10\\
\color{white}\dot{\color{black}0} & \phantom{-}7 & \phantom{-} 17 
\end{bmatrix}

\begin{bmatrix}
I_{1}\\
I_{2}\\
I_{3}
\end{bmatrix}

=

\begin{bmatrix}
\phantom{-}\color{white}\dot{\color{black}0}\\
\phantom{-}\color{white}\dot{\color{black}4}\\
-\color{white}\dot{\color{black}3}
\end{bmatrix}
\]

you'll get

enter image description here

(For other Mac users: in a document inside the text, click on the insert symbol, which looks a bit like a reverse double-stroke P, and click insert equation, you'll be able to verify that it works. Whether or not this is an appropriate question for this site, I cannot judge.)

NOTE: I removed the \vphantom parts I had originally as this seems not to be supported by pages.

7
  • In a case like this, rather than a \vphantom, I’d use a \mathstrut (which is itself a \vphantom, namely \vphantom () everywhere.
    – GuM
    Commented May 25, 2018 at 1:26
  • Also beware that, in the last matrix, -3 should now be {-3} (the \vphantom inserts an empty box, which is a \mathord). The same remark applies to @mas’ answer too.
    – GuM
    Commented May 25, 2018 at 1:41
  • \vphantom is not working for me. Like I said, Pages has a very limited set of Latex. I have tried \phantom and it almost works. The matrices got equal sizes but the alignment is gone.
    – Duck
    Commented May 25, 2018 at 1:55
  • There is a minor typo on your code... on the part you type \phantom{-1}7... I think the correct is \phantom{-}7. Adding the 1 shifts the 7 slightly to the right on my Pages. Anyway, your code is fantastic. Thanks.
    – Duck
    Commented May 26, 2018 at 0:17
  • Let me ask you something. I have another question about latex on mac, that is how to create a box around a formula. I have searched the whole web and nothing works. Do you by any chance know? If you say yes I will open another question, to let you earn a few points... 😃
    – Duck
    Commented May 26, 2018 at 1:38
8

In addition to marmot's answer, you can use mathtools to right justify the numbers:

\documentclass{article}                                                                   
\usepackage{mathtools}                                                                    
\begin{document}                                                                          
\[                                                                                        
\begin{bmatrix*}[r]                                                                       
\vphantom{I_{1}}1 & -1 & -1\\                                                             
\vphantom{I_{1}}0 & 13 & -10\\                                                            
\vphantom{I_{1}}0 & 7 & 17                                                                
\end{bmatrix*}                                                                            
%                                                                                         
\begin{bmatrix}                                                                           
I_{1}\\                                                                                   
I_{2}\\                                                                                   
I_{3}                                                                                     
\end{bmatrix}                                                                             
%                                                                                         
=                                                                                         
%                                                                                         
\begin{bmatrix*}[r]                                                                       
\vphantom{I_{1}} 0\\                                                                      
\vphantom{I_{1}} 4\\                                                                      
\vphantom{I_{1}}-3                                                                        
\end{bmatrix*}                                                                            
\]                                                                                        
\end{document} 

enter image description here

1
  • \vphantom is not working for me. Like I said, Pages has a very limited set of Latex. I have tried \phantom and it almost works. The matrices got equal sizes but the alignment is gone. BTW that is the meaning of having bmatrix and bmatrix*?
    – Duck
    Commented May 25, 2018 at 1:55

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