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<texcode>
\startformula \startalign
v &= u + at \\
h &= ut + \frac12 gt^2 \\
\stopalign \stopformula
</texcode>
Note the \\ in the last line, above.
<texcode>
\startformula \startalign[n=3,align={right,middle,left}]
\NC v \NC = u \NC+ at \NR
\NC h \NC= ut \NC+ \frac12 gt^2 \NR
\stopalign \stopformula
</texcode>
<texcode>
\definemathalignment
[gather]
[n=1,align={middle}]
\startformula \startgather
\NC ax^2 + bx + c = 0 \NR
\NC \text{roots} = \frac{ -b \pm \sqrt{b^2 - 4ac}}{2a} \NR
\stopgather \stopformula
</texcode>
→Defining new alignment structures
* Latex style
<context source=yes text="Note the \\ in the last line, above. This appears as follows: <context">
\startformula \startalign
v &= u + at \\
* Context Style
<texcode>\startformula \startalign \NC v \NC context source= u + at \NR \NC h \NC= ut + \frac12 gt^2 \NR\stopalign \stopformula</texcode> <contextyes>
\startformula \startalign
\NC v \NC = u + at \NR
The above equations were aligned at <code>=</code>. Suppose you also want the <code>+</code> to align. Well, this is simple in context, simply specify the number of columns with <code>\startalign</code>
<texcode>\startformula \startalign[n=3] \NC v \NC = u \NC+ at \NR \NC h \NCcontext source= ut \NC+ \frac12 gt^2 \NR\stopalign \stopformula</texcode> <contextyes>
\startformula \startalign[n=3]
\NC v \NC = u \NC+ at \NR
== Alignment of each column ==
If you want more control over the formatting, and want the middle column to be center aligned, you can do that by
<contextsource=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
This mechanism allows fancier alignments like
<texcodecontext source=yes>\startformula \startalign[n=4,align={1:left,2:right,3:middle,left}] \NC \text{We have} \quad \NC v \NC = u \NC+ at \NR \NC \text{and} \NC h \NC= ut \NC+ \frac12 gt^2 \NR\stopalign \stopformula</texcode> <context>\startformula \startalign[n=4,align={left,right,middle,:left}]
\NC \text{We have} \quad \NC v \NC = u \NC+ at \NR
\NC \text{and} \NC h \NC= ut \NC+ \frac12 gt^2 \NR
aligned equations can be numbered by placing a tag after {{cmd|NR}}
<texcodecontext source=yes>\setuplayout[scale=0.8,width=13cm]
\placeformula \startformula \startalign
\NC v \NC = u + at \NR[eq:v]
\NC h \NC = ut + \frac12 gt^2 \NR[eq:h]
\stopalign \stopformulaEquation ~(\in[eq:v]) tells the final velocity after time ~$t$ and equation ~(\in[eq:h]) tells the distance travelled in time ~$t$.</texcodecontext> The numbering can be changed to a subformula style using {{cmd|placesubformula}} instead of {{cmd|placeformula}} and numbering the subformulas using {{cmd|NR|2=[+][a]}}, {{cmd|NR|2=[+][b]}}, … instead:
<contextsource=yes>
\setuplayout[scale=0.8,width=13cm]
\placeformula placesubformula \startformula \startalign \NC v \NC = u + at \NR[+][eq:v] \NC h \NC = ut + \frac12 gt^2 \NR[+][eq:h]
\stopalign \stopformula
Equation ~(\in[eq:v]) tells the final velocity after time ~$t$ and equation (\in[eq:h]) tells the distance travelled in time ~$t$.
</context>
New alignment can be defined using {{cmd|definemathalignment}}. For example, to emulate <code>gather</code> environment of amsmath, we can use
<contextsource=yes>
\definemathalignment
[gather]
[n=1,align={1:middle}]
\startformula \startgather
</context>
== Cases ==
Context provides a {{cmd|startmathcases}} {{cmd|stopmathcases}} pair to make it easy to get cases. <texcode>\startformula f(x) = \startmathcases \NC x, \NC if $0 \le x \le \frac12$ \NR \NC 1-x ,\NC if $\frac12 \le x \le 1$ \NR\stopmathcases\stopformula</texcode> gives
<contextsource=yes text="gives">
\startformula
\delta_{ij} = f(x) = \startmathcases \NC x, 1 \NC \text{if $0 \le x \le \frac12$ } i = j \NR \NC 1-x ,0 \NC if $\frac12 \le x \le 1$ text{otherwise} \NR \stopmathcases
\stopformula
</context>
The cases environment consists of two columns, separated by {{cmd|NC}}. The second column is by default in text math mode. An alternative way of getting the same result is to define To typeset the second column as a mathcolumn with in text mode, use {{cmd|MCTC}} like so:
<texcode>
\startformula
\delta_{ij} = f(x) = \startmathcases \NC x, 1 \MC TC if \textm{if i = j} 0 \le x \le \frac12 \NR \NC 1-x ,0 \MC \text{if } \frac12 \le x \le 1 TC otherwise \NR \stopmathcases
\stopformula
</texcode>
Each line must end with a {{cmd|NR<}}.
== Numbered Cases ==
[[Category:Math]]
