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Chapters:
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<a href="Introduction.html">1: Introduction</a><br>
<a href="SimpleExample.html">2: Simple example</a><br>
<a href="InvokingGri.html">3: Invocation</a><br>
<a href="GettingMoreControl.html">4: Finer Control</a><br>
<a href="X-Y.html">5: X-Y Plots</a><br>
<a href="ContourPlots.html">6: Contour Plots</a><br>
<a href="Images.html">7: Image Plots</a><br>
<a href="Examples.html">8: Examples</a><br>
<a href="Commands.html">9: Gri Commands</a><br>
<a href="Programming.html">10: Programming</a><br>
<a href="Environment.html">11: Environment</a><br>
<a href="Emacs.html">12: Emacs Mode</a><br>
<a href="History.html">13: History</a><br>
<a href="Installation.html">14: Installation</a><br>
<a href="Bugs.html">15: Gri Bugs</a><br>
<a href="TestSuite.html">16: Test Suite</a><br>
<a href="Acknowledgments.html">17: Acknowledgments</a><br>
<a href="License.html">18: License</a><br>
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Indices:</br>
<a href="ConceptIndex.html"><i>Concepts</i></a><br>
<a href="CommandIndex.html"><i>Commands</i></a><br>
<a href="BuiltinIndex.html"><i>Variables</i></a><br>
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<h3>10.9.4: Binary Operators</h3>
Binary operators act on the <b>top two</b> items on the stack. Most
binary operators replace two items on the stack with one item, e.g.
`<font color="#82140F"><code>{rpn 1 2 /}</code></font>' yields 0.5. However, a few binary operators
replace one pair of items with a new pair of items, e.g. the
`<font color="#82140F"><code>xyusertocm</code></font>' operator replaces an (x,y) pair in user coordinates
with an (xcm,ycm) pair in coordinates of centimeters on the page.
<p>
The binary operators are illustrated below, in rough alphabetical order.
<p>
<dl>
<dt> <tt>{rpn 3 2 +}</tt>
<dd>Add 2 to 3.
<dt> <tt>{rpn 3 2 -}</tt>
<dd>Subtract 2 from 3.
<dt> <tt>{rpn 3 2 *}</tt>
<dd>Multiply 3 by 2.
<dt> <tt>{rpn 3 2 /}</tt>
<dd>Divide 3 by 2.
<dt> <tt>{rpn 3 2 <}</tt>
<dd><p>
Test whether 2 is less than 3, yielding 1. Note: this convention may
be confusing to users who are familiar with HP calculators from
decades past. Present-day calculators use this convention, but
possibly older calculators used the reverse convention, using `<font color="#82140F"><code>></code></font>'
where Gri uses `<font color="#82140F"><code><</code></font>'.
<p>
<dt> <tt>{rpn 3 2 <=}</tt>
<dd>Test whether 2 is less than or equal to 3.
<p>
<dt> <tt>{rpn 3 2 >}</tt>
<dd>Test whether 2 is greater than 3, yielding 0.
<p>
<dt> <tt>{rpn 3 2 >=}</tt>
<dd>Test whether 2 is greater than or equal to 3, yielding 0.
<p>
<dt> <tt>{rpn 3 2 ==}</tt>
<dd>Test whether 2 and 3 are equal, yielding 0. (Do not confuse this with
the asignment operator `<font color="#82140F"><code>=</code></font>', described next.)
<p>
<dt> <tt>{rpn 10 ".ten." =}</tt>
<dd>Assign the value `<font color="#82140F"><code>10</code></font>' to the variable named `<font color="#82140F"><code>.ten.</code></font>'. (Do not
confuse this with the `<font color="#82140F"><code>==</code></font>' equality operator described above.)
<p>
<dt> <tt>{rpn "hello" "\\greeting" =} </tt>
<dd>Assign the value `<font color="#82140F"><code>"hello"</code></font>' to the synonym `<font color="#82140F"><code>\greeting</code></font>'.
<p>
<dt> <tt>{rpn 0 1 &}</tt>
<dd>Test whether 0 and 1 are both true, yielding 0.
<p>
<dt> <tt>{rpn 0 1 |}</tt>
<dd>Test whether either 0 or 1 is true, yielding 1.
<p>
<dt> <tt>{rpn 2 3 exch}</tt>
<dd>Exchange 2 and 3 on the stack, yielding `<font color="#82140F"><code>3 2</code></font>' on the stack. (See
also `<font color="#82140F"><code>pop</code></font>' and `<font color="#82140F"><code>dup</code></font>'.)
<p>
<dt> <tt>{rpn x 0 @}</tt>
<dd>Yields the value of the first number in the x column. A similar form
also works for `<font color="82140F"><code>y</code></font>', etc. (see <a href="ManipulatingColumns.html#ManipulationofColumnsetc">Manipulation of Columns etc</a>).
<p>
<dt> <tt>{rpn 2 3 inf}</tt>
<dd>Pick the smaller of two values, yielding 3. (Opposite to `<font color="#82140F"><code>sup</code></font>'.)
<p>
<dt> <tt>{rpn 2 3 power}</tt>
<dd>Take 2 to the 3rd power, yielding 8. Note: This convention may be
confusing to users who are familiar with HP calculators from decades
past. Present-day calculators use this convention, which they write as
`<font color="#82140F"><code>y^x</code></font>', but older calculators used the reverse convention, labelling
the key `<font color="#82140F"><code>x^y</code></font>'.
<p>
<p>
<dt> <tt>{rpn 2 3 remainder}</tt>
<dd>Calculate the remainder after dividing 2 by 3, yielding 2. The return value
for `<font color="#82140F"><code>{rpn A B remainder</code></font>'} is `<font color="#82140F"><code>B - n * A</code></font>', where `<font color="#82140F"><code>n</code></font>' is
the quotient of `<font color="#82140F"><code>A/B</code></font>', rounded towards zero to an integer. In this
case, `<font color="#82140F"><code>2/3</code></font>' rounds to an `<font color="#82140F"><code>n</code></font>' value of zero, yielding 2 as the
resulting remainder.
<p>
<dt> <tt>{rpn "file" ".dat" strcat}</tt>
<dd>Concatenate the two strings, yielding the string `<font color="#82140F"><code>"file.dat"</code></font>'.
<p>
<dt> <tt>{rpn 2 3 sup}</tt>
<dd>Pick the larger of two values, yielding 3. (Opposite to `<font color="#82140F"><code>inf</code></font>'.)
<p>
</dl>
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