Changes

= Basic Alignment with {{cmd|startalign}} = <context source="yes">\startformula\startalign \NC v \NC = u + at \NR \NC h \NC = ut + \frac12 gt^2 \NR\stopalign\stopformula</context> {{cmd|NC}} stands for new column, {{cmd|NR}} stands for new row. = Changing the number of columns = The above equations were aligned at <code>=</code>. Suppose you also want the <code>+</code> moved to align. Well, this is simple in context, simply specify the number of columns with <code>\startalign</code> <context source=yes>\startformula \startalign[n=3] \NC v \NC = u \NC + at \NR \NC h \NC = ut \NC + \frac12 gt^2 \NR\stopalign \stopformula</context> = Equation numbering with {{cmd|startplaceformula}} = Aligned equations can be numbered by using {{cmd|startplaceformula}} (as usual), and by placing a tag after {{cmd|NR}} <context source=yes>\setuplayout[scale=0.8,width=13cm]\startplaceformula\startformula \startalign \NC v \NC = u + at \NR[eq:v] \NC h \NC = ut + \frac12 gt^2 \NR[eq:h]\stopalign \stopformula \stopplaceformulaEquation~(\in[eq:v]) tells the final velocity after time~$t$ and equation~(\in[eq:h]) tells the distance travelled in time~$t$.</context> == Sub-numbering with {{cmd|startsubformulas}} == The numbering can be changed to a subformula style by encapsulating {{cmd|startplaceformula}} with {{cmd|startsubformulas}} : <context source=yes>\setuplayout[scale=0.8,width=13cm]\startsubformulas[eq:total]\startplaceformula\startformula \startalign \NC v \NC = u + at \NR[eq:v] \NC h \NC = ut + \frac12 gt^2 \NR[eq:h]\stopalign \stopformula \stopplaceformula\stopsubformulas  In~(\in[eq:total]), equation~(\in[eq:v]) tells the final velocity after time~$t$ and equation (\in[eq:h]) tells the distance travelled in time~$t$.</context> = Specifying and defining alignment with {{cmd|definemathalignment}} = If you want more control over the formatting, and want the middle column to be center aligned, you can do that by  <context source=yes>\startformula \startalign[n=3,align={1:right,2:middle,3:left}] \NC v \NC = u \NC+ at \NR \NC h \NC= ut \NC+ \frac12 gt^2 \NR\stopalign \stopformula</context> This mechanism allows fancier alignments like <context source=yes>\startformula \startalign[n=4,align={1:right,2:right,3:middle,4:left}] \NC \text{We have} \quad \NC v \NC = u \NC+ at \NR \NC \text{and} \quad \NC h \NC= ut \NC+ \frac12 gt^2 \NR\stopalign \stopformula</context>  These kind of new alignment can be defined using {{cmd|definemathalignment}}. <context source=yes>\definemathalignment [demom] [n=4,align={1:right,2:right,3:middle,4:left}] \startformula \startdemom \NC \text{We have} \quad \NC v \NC = u \NC+ at \NR \NC \text{and} \quad \NC h \NC= ut \NC+ \frac12 gt^2 \NR\stopdemom \stopformula</context> A second example, to emulate <code>gather<Math/code> environment of amsmath, we can use <context source=yes>\definemathalignment [gather] [n=1,align={1:middle}] \startformula \startgather \NC ax^2 + bx + c = 0 \NR \NC \text{roots} = \frac{ -b \pm \sqrt{b^2 - 4ac}}{2a} \NR\stopgather \stopformula </context> = Cases = == with {{cmd|startmathcases}} (two columns) == Context provides a {{cmd|startmathcases}} {{cmd|stopmathcases}} pair to make it easy to get cases. The cases environment consists of two columns, separated by {{cmd|NC}}. Each line must end with a {{cmd|NR}}. <context source="yes" text="gives">\startformula \startcases[align={right,left},distance=3pt] \NC 2x + 3y \NC = 10 \NR \NC 3x + 2y \NC = 5 \NR \stopcases\stopformula and \startformula\delta_{ij} = \startmathcases \NC 1 \NC \text{if } i = j \NR \NC 0 \NC \text{otherwise} \NR \stopmathcases\stopformula</context> The second column is by default in math mode. To typeset the second column in text mode, use {{cmd|TC}}: <context source="yes" text="gives">\startformula\delta_{ij} = \startmathcases \NC 1 \TC if \m{i = j} \NR \NC 0 \TC otherwise \NR \stopmathcases\stopformula</context> == with {{cmd|definemathmatrix}} == One of the powerful structures in displaying mathematical formulas is the possibility of defining custom maths alignment.For instance the following definition  <context source="yes">\definemathmatrix [alignedcases] % creates 2 new commands \startalignedcases \stopalignedcases [align={right,left,left}, distance=3pt, left={\left\{}, right={\right.}, style=\displaystyle] The following formula is displayed in two lines with an appropriate alignment of the equations: \startformula\startalignedcases \NC -\Delta u + g(u) \NC{} = f \NC \quad\mbox{in } \Omega\NR \NC {\partial u \over \partial {\bf n} } \NC{} = h(u) \NC \quad\mbox{on } \partial\Omega \NR\stopalignedcases\stopformula</context> == Numbering cases with {{cmd|startplaceformula}} plus {{cmd|startsubformulas}} == As you may expect: <context source="yes" text="gives">\startsubformulas\startplaceformula\startformula \startcases[align={right,left},distance=3pt] \NC 2x + 3y \NC = 10 \NR[eq:a] \NC 3x + 2y \NC = 5 \NR[eq:b] \stopcases\stopformula\stopplaceformula\stopsubformulas</context> = Links = See [[Math#Links]] [[Category:MathMultiline_equations]]