= Defining with {{cmd|definemathmatrix}} = In order moved to type matrices in math formulas, there is the command {{cmd|definemathmatrix}}. Once a certain type of matrix is defined, one can also add a simple command in order to type matrices in a Matlab or Scilab format. Here are a few examples. <context source="yes">\setuplayout[scale=0.8,width=13cm] \definemathmatrix[pmatrix] % defining matrix with parentheses [matrix:parentheses] [simplecommand=pmatrix] \definemathmatrix[bmatrix] % defining matrix with brackets [matrix:brackets] [simplecommand=bmatrix] \definemathmatrix[determinant] % defining determinant with bars [matrix:bars] [simplecommand=thedeterminant] Let $A$ be the matrix\startformulaA = \startpmatrix \NC 2 \NC 3 \NR \NC 1 \NC 2 \NR \stoppmatrix\stopformula Show that\startformula{\rm det}(A) = \startdeterminant \NC 2 \NC 3 \NR \NC 1 \NC 2 \NR \stopdeterminant = 1\stopformula Compute the matrix $AB$ where $B$ is the matrix\startformulaB = \pmatrix{2, -3 ; -1, 2}.\stopformula </context> = Formatting delimiters with <tt>left</tt> and <tt>right</tt> = It is possible to have different delimiters on the left and on the right. For instance:<context source = yes >\definemathmatrix[pvmatrix] [left={\left(\thinspace}, right={\thinspace\right|}] \definemathmatrix[rpmatrix] [left={\left.\thinspace}, right={\thinspace\right]}] \startformula \startpvmatrix \NC 11 \NC 12 \NC 13 \NR \NC 21 \NC 22 \NC 23 \NR \NC 31 \NC 32 \NC 33 \NR \stoppvmatrix \startrpmatrix \NC 0 \NR \NC 1 \NR \NC 2 \NR \stoprpmatrix\stopformula </context> = Block matrices with vertical and/or horizontal lines = In ConTeXt LMTX beginning version 2020-11-27, it is possible to create « block » matrices where the blocks are separated by vertical or horizontal lines (respectively {{cmd|VL}} and {{cmd|HL}}). For instance the above example can be typeset more easily by the following : <context source = yes>\definemathmatrix[mymatrix] [left={\left\lparent\thinspace}, % instead of the left parenthesis, one can use any other fence right={\thinspace\right\rparent}] % instead of the right parenthesis, one can use any other fence \starttextHere is $3 \times 3$ matrix with a column added to it\startformula \startmymatrix \NC 11 \NC 12 \NC 13 \VL 0 \NR \NC 21 \NC 22 \NC 23 \VL 1 \NR \NC 31 \NC 32 \NC 33 \VL 2 \NR \stopmymatrix\stopformulaHere is a block matrix:\startformula \startmymatrix \NC A \VL B \NR \HL \NC C \VL D \NR \stopmymatrix\stopformula</context> The two commands {{cmd|VL}} and {{cmd|HL}} take an optional parameter which defines the thickness of the rule and its color. So {{cmd|HL|[3,red]}} will produce a red horizontal rule three times thicker than the default matrix rule. The rule thickness for a specific matrix is defined with the {{code|1=[rulethickness=]}} parameter of {{cmd|definemathmatrix}}. <context source=yes>\definemathmatrix[mymatrix][matrix:parentheses][rulethickness=2pt] \starttext\startformula \startmymatrix \NC A \VL[3,green] B \NR \HL[10,red] \NC C \VL D \NR \stopmymatrix\stopformula<Math/context> A {{cmd|VL}} counts as a hidden cell. To interrupt a vertical line, use an empty cell. <context source=yes>\definemathmatrix[mymatrixMatrices][matrix:parentheses] Weird matrix\startformula \startmymatrix \NC A \VL B \NR \HL[red] \NC C \NC D \NR \stopmymatrix\stopformula This allows things like \startformula \startmymatrix \NC A \VL B \NR \HL \NC \NC C \NC \NR \stopmymatrix \qquad \startmymatrix \NC A_1 \VL B_1 \NR \HL \NC \vdots \NC \vdots \NC \vdots \NR \HL \NC A_n \VL B_n \NR \stopmymatrix\stopformula </context>