2

I try to make matrix multiplication like

\begin{align*}
~ & \begin{bmatrix}
m_{0} & m_{1} & m_{2} & m_{3} \\
m_{4} & m_{5} & m_{6} & m_{7} \\
m_{8} & m_{9} & m_{10} & m_{11} \\
m_{12} & m_{13} & m_{14} & m_{15}
\end{bmatrix} \\
\begin{bmatrix}
v_{0} & v_{1} & v_{2} & v_{3}
\end{bmatrix} & \begin{bmatrix}
r_{0} & r_{1} & r_{2} & r_{3}
\end{bmatrix}
\end{align*}

But vector r is not correctly align (vertically) with matrix m. Moreover, I don't want specifics packages (I use Latext inside MathJax).

Do you have some tips for me ?

Thanks

EDIT
I add another way with same issue:

\[
\begin{array}{cc}
~ & \begin{bmatrix}
m_{0} & m_{1} & m_{2} & m_{3} \\
m_{4} & m_{5} & m_{6} & m_{7} \\
m_{8} & m_{9} & m_{10} & m_{11} \\
m_{12} & m_{13} & m_{14} & m_{15}
\end{bmatrix} \\
\begin{bmatrix}
v_{0} & v_{1} & v_{2} & v_{3}
\end{bmatrix} &
\begin{bmatrix}
r_{0} & r_{1} & r_{2} & r_{3}
\end{bmatrix}
\end{array}
\]

I want this kind of design enter image description here

1
  • 1
    please provide complete but small document with your matrix. what is \X? welcome to tex.se!
    – Zarko
    Mar 27, 2018 at 14:30

2 Answers 2

1

The big bracket has different side bearings than the smaller one.

Add some visually determined spacing:

\documentclass{article}
\usepackage{amsmath,calc}

\begin{document}

\begin{align*}
& \begin{bmatrix}
  m_{0} & m_{1} & m_{2} & m_{3} \\
  m_{4} & m_{5} & m_{6} & m_{7} \\
  m_{8} & m_{9} & m_{10} & m_{11} \\
  m_{12} & m_{13} & m_{14} & m_{15}
  \end{bmatrix}
\\
  \begin{bmatrix}
  v_{0} & v_{1} & v_{2} & v_{3}
  \end{bmatrix}
& \mspace{5mu}
  \bigl[\begin{matrix}
  \makebox[\widthof{$m_{12}$}]{$r_{0}$} &
  \makebox[\widthof{$m_{13}$}]{$r_{1}$} &
  \makebox[\widthof{$m_{14}$}]{$r_{2}$} &
  \makebox[\widthof{$m_{15}$}]{$r_{3}$}
  \end{matrix}
  \mspace{5mu}
  \bigr]
\end{align*}

\end{document}

enter image description here

2
  • I valid solution BUT I can't use calc package on MathJax. I think now I must find a way to improve my Latex/MathJax. Thanks !
    – Rominitch
    Mar 28, 2018 at 6:51
  • 1
    @Rominitch MathJax has nothing to do with this site.
    – egreg
    Mar 28, 2018 at 6:52
1

First of all, there is nothing here to align, why do you use align*? two \[ and \] are enough. Also, this is a vector-matrix multiplication, the inner dimensions must match and the result taking outer dimensions, so v[1-by-4] x M[4-by-4] = r[1-by-4]. I re-ordered the multiplication accordingly and removed align*.

\documentclass{article}
\usepackage{amsmath}
\begin{document}   

\[
\begin{bmatrix}
v_{0} & v_{1} & v_{2} & v_{3}
\end{bmatrix} 
\begin{bmatrix}
m_{0} & m_{1} & m_{2} & m_{3} \\
m_{4} & m_{5} & m_{6} & m_{7} \\
m_{8} & m_{9} & m_{10} & m_{11} \\
m_{12} & m_{13} & m_{14} & m_{15}
\end{bmatrix} =
\begin{bmatrix}
r_{0} & r_{1} & r_{2} & r_{3}
\end{bmatrix}
\]

\end{document}

enter image description here

2
  • I don't search to write on one row but two
    – Rominitch
    Mar 27, 2018 at 15:32
  • @Rominitch - Please post an image of the desired alignment, your question is not clear; you say But vector r is not correctly align (vertically) with matrix m, r and m are on two different lines, in this case you can only horizontally align them.
    – AboAmmar
    Mar 27, 2018 at 16:37

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