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<div><a href="index.html" title="">Macaulay2Doc</a> > <a href="___The_sp__Macaulay2_splanguage.html" title="">The Macaulay2 language</a> > <a href="_using_spfunctions.html" title="">using functions</a></div>
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<div><h1>using functions</h1>
<div>There are many functions in Macaulay2 that do various things. You can get a brief indication of what a function does by typing its name.<table class="examples"><tr><td><pre>i1 : sin
o1 = sin
o1 : CompiledFunction</pre>
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In this case, we see that the function <a href="_sin.html" title="compute the sine">sin</a> takes a single argument <tt>x</tt>. We apply a function to its argument by typing them in adjacent positions. It is possible but not necessary to place parentheses around the argument.<table class="examples"><tr><td><pre>i2 : sin 1.2
o2 = .932039085967226
o2 : RR (of precision 53)</pre>
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<tr><td><pre>i3 : sin(1.2)
o3 = .932039085967226
o3 : RR (of precision 53)</pre>
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<tr><td><pre>i4 : sin(1.0+0.2)
o4 = .932039085967226
o4 : RR (of precision 53)</pre>
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In parsing the operator <a href="_^.html" title="a binary operator, usually used for powers">^</a> takes precedence over adjacency, so the function is applied after the power is computed in the following code. This may not be what you expect.<table class="examples"><tr><td><pre>i5 : print(10 + 1)^2
121</pre>
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Some functions take more than one argument, and the arguments are separated by a comma, and then parentheses are needed.<table class="examples"><tr><td><pre>i6 : append
o6 = append
o6 : CompiledFunction</pre>
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<tr><td><pre>i7 : append({a,b,c},d)
o7 = {a, b, c, d}
o7 : List</pre>
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Some functions take a variable number of arguments.<table class="examples"><tr><td><pre>i8 : join
o8 = join
o8 : CompiledFunction</pre>
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<tr><td><pre>i9 : join({a,b},{c,d},{e,f},{g,h,i})
o9 = {a, b, c, d, e, f, g, h, i}
o9 : List</pre>
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Functions, like anything else, can be assigned to variables. You may do this to provide handy private abbreviations.<table class="examples"><tr><td><pre>i10 : ap = append;</pre>
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<tr><td><pre>i11 : ap({a,b,c},d)
o11 = {a, b, c, d}
o11 : List</pre>
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