abs(x)		compute the absolute value of <i>x</i>
sign(x)		positive / negative sign (-1 with <i>x</i> &lt; 0, 1 with <i>x</i> &gt;= 0)
int(x)		round to integer, toward zero
gauss(x)	largest integral value not greater than <i>x</i>
frac(x)		remainder
round(x, digit)	round the number <i>x</i>, away from zero.\n<i>digit</i> is the number of digits to which you want to round <i>x</i>.
min(a, b, c, ...)	The smallest value of arguments
max(a, b, c, ...)	The largest value of arguments
sumsq(a, b, c, ...)	square sum of arguments
sqr(x)		squaring
sqrt(x)		square root
exp(x)		base-e exponential function (<i>x</i> &lt;= 690)
expm1(x)	exp(<i>x</i>)-1.\nThe result is computed in a way that is accurate\neven if the value of <i>x</i> is near zero.
ln(x)		natural logarithmic function
ln1p(x)		ln(1+<i>x</i>).\nThe result is computed in a way that is accurate\neven if the value of <i>x</i> is near zero.
log(x)		base-10 logarithmic function
log1p(x)	log(1+<i>x</i>).\nThe result is computed in a way that is accurate\neven if the value of <i>x</i> is near zero.
sin(x)		sine function
cos(x)		cosine function
tan(x)		tangent function
asin(x)		arc sine function
acos(x)		arc cosine function
atan(x)		arc tangent function
sinh(x)		hyperbolic sine function
cosh(x)		hyperbolic cosine function
tanh(x)		hyperbolic tangent function
asinh(x)	inverse hyperbolic sine function
acosh(x)	inverse hyperbolic cosine function
atanh(x)	inverse hyperbolic tangent function
fmod(x, y)	compute the floating-point remainder of dividing <i>x</i> by <i>y</i>
rand(x)		returns a random value equally distributed over the range [0..<i>x</i>)
srand(x)	Sets the seed for the random number generator which is used by the <b>rand</b>() function
theta(x)	staircase function (1 if <i>x</i> &gt;= 0, 0 otherwise)
delta(x)	Kronecker delta (1 when <i>x</i> = 0, 0 otherwise)
gamma(x)	gamma function
icgam(m, x)	incomplete gamma function
erf(x)		error function erf(<i>x</i>)
erfc(x)		complementary error function erfc(<i>x</i>)
qinv(x)		inverse complementary error function
ei(x)		compute the exponential integral Ei(<i>x</i>)
beta(x, y)	beta function
icbeta(a, b, x)	incomplete beta function
jn(n, x)	compute the regular cylindrical Bessel function of order <i>n</i>, J<sub><i>n</i></sub>(|<i>x</i>|)
yn(n, x)	compute the irregular cylindrical Bessel function of order <i>n</i>, Y<sub><i>n</i></sub>(|<i>x</i>|)
in(n, x)	compute the regular modified cylindrical Bessel function of order |<i>n</i>|, I<sub><i>n</i></sub>(|<i>x</i>|)
kn(n, x)	compute the irregular modified cylindrical Bessel function of order |<i>n</i>|, K<sub><i>n</i></sub>(|<i>x</i>|)
jl(l, x)	compute the regular spherical Bessel function of order |<i>l</i>|, j<sub><i>l</i></sub>(|<i>x</i>|)
yl(l, x)	compute the irregular spherical Bessel function of order |<i>l</i>|, y<sub><i>l</i></sub>(|<i>x</i>|)
jnu(nu, x)	compute the regular cylindrical Bessel function of fractional order |<i>nu</i>|, J<sub><i>nu</i></sub>(|<i>x</i>|)
ynu(nu, x)	compute the irregular cylindrical Bessel function of fractional order |<i>nu</i>|, Y<sub><i>nu</i></sub>(|<i>x</i>|)
inu(nu, x)	compute the regular modified Bessel function of fractional order |<i>nu</i>|, I<sub><i>nu</i></sub>(|<i>x</i>|)
knu(nu, x)	compute the irregular modified Bessel function of fractional order |<i>nu</i>|, K<sub><i>nu</i></sub>(|<i>x</i>|)
pn(l, x)	evaluate the Legendre polynomial P<sub>l</sub>(<i>x</i>) for a specific value of <i>l, x</i> subject to <i>l</i> &gt;= 0, |<i>x</i>| &lt;= 1
lgn(n, a, x)	evaluate the generalized Laguerre polynomials L<sup><i>a</i></sup><sub><i>n</i></sub>(<i>x</i>) for <i>a</i> &gt; -1, <i>n</i> &gt;= 0
hn(n, x)	Hermite polynomials
tn(n, x)	Chebyshev polynomials
zeta(s)		compute the Riemann zeta function zeta(s) for arbitrary <i>s</i>, <i>s</i> != 1
zeta_int(n)	compute the Riemann zeta function zeta(n) for integer <i>n</i>, <i>n</i> != 1
zetam1(s)	compute zeta(<i>s</i>) - 1 for arbitrary <i>s</i>, <i>s</i> != 1
zetam1_int(n)	compute zeta(<i>n</i>) - 1 for integer <i>n</i>, <i>n</i> != 1
choose(n, m)	the combinatorial factor <i>n</i> choose <i>m</i>: <i>n!/(m!(n-m)!)</i>
mjd(year, month, day, hour, min, sec)	Modified Julian Date (date and time are given in UTC)
unix2mjd(time)	Modified Julian Date\n<i>time</i> represents the number of seconds elapsed since the Epoch,\n1970-01-01 00:00:00 +0000 (UTC))
mjd2unix(mjd)	time represents the number of seconds elapsed since the Epoch at <i>mjd</i>
mjd2year(mjd)	year of Gregorian calendar corresponding to Modified Julian Day <i>mjd</i>
mjd2month(mjd)	month of Gregorian calendar corresponding to Modified Julian Day <i>mjd</i>
mjd2day(mjd)	Gregorian calendar day corresponding to Modified Julian Day <i>mjd</i>
mjd2wday(mjd)	The day of the week as a decimal range 1 to 7, Monday being 1 corresponding to <i>mjd</i>
mjd2yday(mjd)	The day of the year as a decimal number (range 001 to 366) corresponding to <i>mjd</i>
time()		returns the time as the number of seconds since the Epoch,\n1970-01-01 00:00:00 +0000 (UTC)
eq(x, y, prec)	True (= 1) when <i>x</i> == <i>y</i>.\nThe number of digits of comparison can be specified with <i>prec</i>\n(<i>prec</i> == 0 is exact match).
neq(x, y, prec)	True (= 1) when <i>x</i> != <i>y</i>.\nThe number of digits of comparison can be specified with <i>prec</i>\n(<i>prec</i> == 0 is exact match).
ge(x, y, prec)	True (= 1) when <i>x</i> &gt;= <i>y</i>.\nThe precision allows you to specify the number of digits for comparison\n(<i>prec</i> == 0 does not specify the number of digits).
gt(x, y, prec)	True (= 1) when <i>x</i> &gt; <i>y</i>.\nThe precision allows you to specify the number of digits for comparison\n(<i>prec</i> == 0 does not specify the number of digits).
le(x, y, prec)	True (= 1) when <i>x</i> &lt;= <i>y</i>.\nThe precision allows you to specify the number of digits for comparison\n(<i>prec</i> == 0 does not specify the number of digits).
lt(x, y, prec)	True (= 1) when <i>x</i> &lt; <i>y</i>.\nThe precision allows you to specify the number of digits for comparison\n(<i>prec</i> == 0 does not specify the number of digits).
not(x)		True (= 1) when <i>x</i> == 0
or(x, y)	True (= 1) when (<i>x</i> != 0) or (<i>y</i> != 0)
and(x, y)	True (= 1) when (<i>x</i> != 0) and (<i>y</i> != 0)
xor(x, y)	True (= 1) when (<i>x</i> != 0) xor (<i>y</i> != 0)
size(a)	number of elements of array <i>a</i>
sort(a, ignore_case)	sort elements of array <i>a</i>\nfold lower case to upper case characters when <i>ignore_case</i> is not zero.
rsort(a, ignore_case)	reverse sort elements of array <i>a</i>\nfold lower case to upper case characters when <i>ignore_case</i> is not zero.
pop(a ,n)		remove the last <i>n</n> elements of array <i>a</i> (<i>n</i> = 0 is as same as <i>n</i> = 1).\nReturns the new size of the array.
push(a, x)	adds new element <i>x</i> to the end of an array <i>a</i>.\nReturns the new size of the array.
shift(a, n)	remove the first <i>n</i> elements of array <i>a</i> (<i>n</i> = 0 is as same as <i>n</i> = 1).\nReturns the new size of the array.
unshift(a, x)	adds new element <i>x</i> to the beginning of an array <i>a</i>.\nReturns the new size of the array.
array(a, v1, v2, ...)	initialize an array <i>a</i> with the rest arguments\nreturn the number of elements of the array
array_sum(a)	returns the sum of the elements of array <i>a</i>
array_sumsq(a)	returns the square sum of the elements of array <i>a</i>
array_average(a)	return the average of the elements of array <i>a</i>
array_stdevp(a)	return the standard deviation of the elements of array <i>a</i>
array_stdev(a)	return the corrected sample standard deviation of the elements of array <i>a</i>
array_max(a)	returns the maximum value contained in array <i>a</i>
array_min(a)	returns the minimum value contained in array <i>a</i>
array_clear(a)	set the number of elements of the array <i>a</i> to 0
array_compact(a)	Remove non-numeric values from the elements of the array of array <i>a</i>\nand return the number of elements after removal
array_copy(dest, src)	copy the contents of the array <i>src</i> to the array <i>dest</i>.\n(return the number of copied elements)
m(i, x)		assigns <i>x</i> to the <i>i</i>-th memory (<i>i</i> = 0 to 65535)\nthe index from the tail when <i>i</i> is negative\n(return <i>x</i>)
rm(i)		the value of the current <i>i</i>-th memory (<i>i</i> = 0 to 65535),\nthe index from the tail when <i>i</i> is negative
cm(x, n)	initialize <i>n</i> memories from the beginning with <i>x</i>\ninitialize whole memory when <i>n</i> is 0\nand <i>n</i> memories from the end when <i>x</i> is negative\n(return <i>x</i>)
am(a)		copy the contents of the array <i>a</i> to the memory\n(return the number of copied elements)
draw_rect(x, y, w, h, stroke, fill)	draw a rectangle with (<i>x, y</i>) and (<i>x + w, y + h</i>) as diagonal vertices.\nWhen <i>stroke</i> and <i>fill</i> are 0, do not draw contours and fills respectively.
draw_arc(x, y, rx, ry, start, arc, pieslice, stroke, fill, close)	draw an arc with the X direction radius <i>rx</i> and the Y direction radius <i>ry</i> centered on (<i>x, y</i>).\n<i>start</i> and <i>arc</i> specify start angle and arc angle respectively.\nWhen <i>stroke</i> and <i>fill</i> are 0, do not draw contours and fills respectively.\nIf <i>pieslice</i> is not 0, draw a sector.\nIf <i>close</i> is not 0, close the outline.
draw_mark(x, y, size)	draw a mark on (<i>x, y</i>). \nThe size of a mark can be specified with <i>size</i>.\nWhen <i>size</i> is 0, specification of the file object is used.
draw_line(x1, y1, x2, y2, arrow, size)	draw a line form (<i>x1, y1</i>) to (<i>x2, y2</i>).\nWhen <i>arrow</i> is 1, 2 or 3, draw arrow end, begin and both side of the line respectively.\nThe size of a arrow can be specified with <i>size</i>.\nWhen <i>size</i> is 0, specification of the file object is used.
draw_polyline(ax, ay)	connect coordinates (<i>ax</i>[0], <i>ay</i>[0]), (<i>ax</i>[1], <i>ay</i>[1]), ... by polyline.
draw_polygon(ax, ay, stroke, fill)	draw polygon defined by coordinates (<i>ax</i>[0], <i>ay</i>[0]), (<i>ax</i>[1], <i>ay</i>[1]), ....\nwhen <i>stroke</i> is 0, do not draw contours.\n<i>fill</i> can be specified with one of\n<b>FILL_RULE_NONE</b>, <b>FILL_RULE_EVEN_ODD</b> or <b>FILL_RULE_WINDING</b>.
draw_errorbar(x, y, erx, ery, size)	draw errorbars from (<i>x - erx, y</i>) to (<i>x + erx, y</i>) and\nfrom (<i>x, y - ery</i>) to (<i>x, y + ery</i>).\nThe length of ticks can be specified with <i>size</i>.\nWhen <i>size</i> is 0, specification of the file object is used.
draw_errorbar2(x1, y1, x2, y2, size)	draw an errorbar from (<i>x1, y1</i>) to (<i>x2, y2</i>).\nThe length of ticks can be specified with <i>size</i>.\nWhen <i>size</i> is 0, specification of the file object is used.
fit_prm(id, x)	When the plot type of the data object with <i>id</i> is fit,\nthe value of the field "%0<i>x</i>" of the corresponding fit object.
fit_calc(id, x)	When the plot type of the data object with <i>id</i> is fit,\nthe corresponding fit result f(<i>x</i>) is calculated.
fit_solve(id, y, x0, x1)	When the plot type of the data object with <i>id</i> is fit,\ncalculate x such that f(x) = <i>y</i> for the corresponding fit result f(x).\nThe initial value of x is specified by <i>x0</i> and <i>x1</i>.\nIf <i>x1</i> is 0, the Newton method is used;\notherwise, the dichotomy method is used.\nIf the calculation is not successful, it returns UNDEF.
line_number()	File line number being processed (1st line is 1)
isnormal(x)	True if <i>x</i> is a normal number
isbreak(x)	True if <i>x</i> is <b>BREAK</b>
iscont(x)	True if <i>x</i> is <b>CONT</b>
isnan(x)	True if <i>x</i> is <b>NAN</b>
isundef(x)	True if <i>x</i> is <b>UNDEF</b>
sum(x)		Integration
dif(x)		Difference
color(i, x)	<i>i</i> = 0: Set the R value to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 1: Set the G value to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 2: Set the B value to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 3: Set the R, G and B values to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 4: Set the R2 value to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 5: Set the G2 value to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 6: Set the B2 value to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 7: Set the R2, G2 and B2 values to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\n<i>i</i> = 8: Set the R, G and B values to be hexadecimal color of <i>x</i>\n<i>i</i> = 9: Set the R2, G2 and B2 values to be hexadecimal color of <i>x</i>
obj_color(id, obj)	Set the R, G, B, R2, G2 and B2 values to the same value as the instance of <i>obj</i> whose ID is <i>id</i>.\n<i>obj</i> is one of <b>DATA_OBJ</b>, <b>PATH_OBJ</b>, <b>ARC_OBJ</b>, <b>MARK_OBJ</b> or <b>TEXT_OBJ</b>.
alpha(x, i)	Set A (<i>i</i> == 1) or A2 (<i>i</i> == 2) values to <i>x</i> (0 &lt;= <i>x</i> &lt; 256)\nwhen <i>i</i> == 0, set A and A2 values to <i>x</i>
obj_alpha(id, obj)	Set the A and A2 value to the same value as the instance of <i>obj</i> whose ID is <i>id</i>.\n<i>obj</i> is one of <b>DATA_OBJ</b>, <b>PATH_OBJ</b>, <b>ARC_OBJ</b>, <b>MARK_OBJ</b> or <b>TEXT_OBJ</b>.
rgb(r, g, b)	Set the R, G and B values of the color to <i>r, g, b</i> (0 &lt;= <i>r, g, b</i> &lt;= 1)
rgb2(r, g, b)	Set the R2, G2 and B2 values of the color to <i>r, g, b</i> (0 &lt;= <i>r, g, b</i> &lt;= 1)
hsb(h, s, b)	Set the R, G and B values of the color to <i>h, s, b</i> (0 &lt;= <i>h, s, b</i> &lt;=1) from the HSB value
hsb2(h, s, b)	Set the R2, G2 and B2 values of the color to <i>h, s, b</i> (0 &lt;= <i>h, s, b</i> &lt;=1) from the HSB value
marksize(x)	Set mark size to <i>x</i>
marktype(x)	Set mark type to <i>x</i>
if(x, ex1, ex2)	evaluate <i>ex1</i> when <i>x</i> != 0, evaluate <i>ex2</i> otherwise
unless(x, ex1, ex2)	evaluate <i>ex2</i> when <i>x</i> != 0, evaluate <i>ex1</i> otherwise
for(m, begin, end, step, ex)	Set the value in <i>step</i> from <i>begin</i> to <i>end</i> to the <i>m</i>-th memory and repeat <i>ex</i>.\nWhen <i>m</i> is negative, no setting to memory is done.\nReturns the value of <i>ex</i> evaluated last.
prog1(arg1, arg2, ...)	Evaluate the arguments and return the evaluated value of the first argument
prog2(arg1, arg2, ...)	Evaluate the arguments and return the evaluated value of the second argument
progn(arg1, arg2, ...)	Evaluate the arguments and return the evaluated value of the last argument
string($str, value)	Converts <i>value</i> to a string and set to <i>$str</i>.\nReturn the value.
puts($str)	Show <i>$str</i> in the information window.\nReturn the length of the string <i>$str</i> in characters.
printf($format, v1, v2, ...)	Converts <i>v1, v2, ...</i> to a string according to <i>$format</i>\nand show in the information window.\nReturn the length of the string <i>$str</i> in characters.
sprintf($str, $format, v1, v2, ...)	Converts <i>v1, v2, ...</i> to a string according to <i>$format</i>\nand set to <i>$str</i>.\nReturn the length of the string <i>$str</i> in characters.
string_float($str)	Converts the string <i>$str</i> to a floating-point value and return the value.
string_float_array(dest, $ary)	Converts the string element of the array <i>$ary</i>\nto a floating-point value\nand set them to the array <i>dest</i>.
string_length($str)	Return the length of the string <i>$str</i> in characters.
string_up($dest, $src)	Converts all lowercase ASCII letters to uppercase ASCII letters in the string <i>$src</i> and set to the string <i>$dest</i>.
string_down($dest, $src)	Converts all uppercase ASCII letters to lowercase ASCII letters in the string <i>$src</i> and set to the string <i>$dest</i>.
string_strip($str)	Removes leading and trailing whitespace from the string <i>$str</i>.
string_append($dest, $src)	Adds the string <i>$src</i> onto the end of the string <i>$dest</i>.
string_prepend($dest, $src)	Adds the string <i>$src</i> onto the start of the string <i>$dest</i>.
string_insert($dest, $src, pos)	Inserts the string <i>$src</i> into the string <i>$dest</i> at the position <i>pos</i>.
string_join($dest, $sep, $array)	Joins a number of strings in the array <i>$array</i>\ntogether to form one long string <i>$dest</i>,\nwith the optional separator <i>$sep</i>inserted between each of them.
string_reverse($dest, $src)	Reverses the UTF-8 string <i>$src</i> and set to the string <i>$dest</i>.
string_compare($str1, $str2, ignore_case)	Compare two strings, ignoring the case of ASCII characters when <i>ignore_case</i> is not zero.
string_match($str, $regexp, ignore_case)	Scans for a match in the string <i>$str</i> for the regular expression pattern <i>$regexp</i>.\nReturn non-zero value if the string matched, zero otherwise.
string_truncate($str, len)	Cuts off the end of the string <i>$str</i>, leaving the first <i>len</i> characters.
string_erase($str, pos, len)	Removes <i>len</i> characters from the string <i>$str</i>, starting at position <i>pos</i>.
string_substring($dest, $src, start, end)	Copies a substring out of a UTF-8 encoded string <i>$src</i>.\nThe substring will contain <i>end</i> - <i>start</i> characters.
string_split($dest, $src, $separator, use_regexp)	Splits the string <i>$src</i> into pieces, using the given <i>$separator</i>.\nEach strings are saved in the array <i>$dest</i>\n<i>$separator</i> is treated as a regular expression\nwhen <i>use_regexp</i> is not 0.\nLetters in <i>$separator</i> match both upper- and lowercase letters\nwhen <i>use_regexp</i> is 2.
string_split_float(dest, $src, $separator, use_regexp)	Splits the string <i>$src</i> into pieces, using the given <i>$separator</i>.\nEach strings are converted to float value and saved in the array <i>dest</i>\n<i>$separator</i> is treated as a regular expression\nwhen <i>use_regexp</i> is not 0.\nLetters in <i>$separator</i> match both upper- and lowercase letters\nwhen <i>use_regexp</i> is 2.
string_replace($dest, $src, $regexp, $replacement, ignore_case)	Replaces all occurrences of the regular expression pattern in <i>$regex</i> with the <i>$replacement</i> text.\nBackreferences of the form '\\number' or '\\g&lt;number&gt;' in the replacement text are interpolated\nby the number-th captured subexpression of the match,\n'\\g&lt;name&gt;' refers to the captured subexpression with the given name.\n'\\0' refers to the complete match,\nbut '\\0' followed by a number is the octal representation of a character.\nLetters in <i>$regex</i> match both upper- and lowercase letters\nwhen <i>ignore_case</i> is not zero.
string_column($dest, index)	Set <i>index</i>th column in the reading data-line to the string <i>$dest</i>.
draw_text($str, x, y, dir)	Draw the string <i>$str</i> at (<i>x, y</i>).\nDirection is specified by <i>dir</i>.
draw_text_raw($str, x, y, dir)	Draw the raw string <i>$str</i> at (<i>x, y</i>).\nDirection is specified by <i>dir</i>.
getobj($obj, $field, id)	Return the value of the <i>$field</i> of the <i>$obj</i> object which ID is <i>id</i>.\nThe field type must be int, bool, enum or double.
getobj_string($str, $obj, $field, id)	Set the value of the <i>$field</i> of the <i>$obj</i> object which ID is <i>id</i> to the variable <i>$str</i>.\nThe field type must be char*.\nReturn the length of the string <i>$str</i> in characters.
getobj_array(array, $obj, $field, id)	Set values of the <i>$field</i> of the <i>$obj</i> object which ID is <i>id</i> to the array <i>array</i>.\nThe field type must be char*[], double[] or int[].\nRetuern the number of elements saved to the array.
map(dest, src, item, ex)	Evaluate <i>ex</i> for each element of the array <i>src</i>\nand set them to the array <i>dest</i>.\nThe element of the array can be referred by the variable <i>item</i>.
reduce(a, item, result, ex)	Evaluate <i>ex</i> for each element of the array <i>a</i>\nand return last evaluated value of <i>ex</i>.\nThe element of the array and the result of previous evaluation\ncan be referred by the variable <i>item</i> and <i>result</i>.
each(a, item, ex)	Evaluate <i>ex</i> for each element of the array <i>a</i>.\nThe element of the array can be referred by the variable <i>item</i>.
each_with_index(a, item, index, ex)	Evaluate <i>ex</i> for each element of the array <i>a</i>.\nThe element of the array and the loop count can be referred\nby the variable <i>item</i> and <i>index</i> respectively.
zip(a1, a2, item1, item2, ex)	Evaluate <i>ex</i> for each element of two arrays <i>a1</i> and <i>a2</i>.\nThe elements of the arrays can be referred by the variable <i>item1</i> and <i>item2</i>.
zip_map(dest, src1, src2, item1, item2, ex)	Evaluate <i>ex</i> for each element of two arrays <i>src1</i> and <i>sec2</i>\nand set them to the array <i>dest</i>..\nThe elements of the arrays can be referred by the variable <i>item1</i> and <i>item2</i>.
filter(dest, src, item, ex)	Find elements in the array <i>src</i>\nthat satisfies that the evaluated value of <i>ex</i> is true\nand set them to the array <i>dest</i>.\nAn element of the array <i>src</i> can be referred by the variable <i>item</i>.
find(a, item, ex)	Returns the value of the first element in the array <i>a</i>\nthat satisfies that the evaluated value of <i>ex</i> is true.\nAn element of the array can be referred by the variable <i>item</i>.
index(a, item, ex)	Returns the first index at which a given element in the array <i>a</i>\nthat satisfies that the evaluated value of <i>ex</i> is true.\nAn element of the array can be referred by the variable <i>item</i>.
times(n, index, ex)	Repeat <i>ex</i> <i>n</i> times.\nThe loop count can be referred by the variable <i>index</i>.
text_align(x, y)	Set alignment of a text drawing.\n<i>x</i> and <i>y</i> represent alignment of parallel and normal direction respectively.\n(0 &lt;= <i>x, y</i> &lt;= 1)
text_font(font)		Set font setting of drawing texts.\nThe value <i>font</i> 0, 1 and 2 represent "Sans-serif", "Serif" and "Monospace" respectively.
text_style(style)	Set font style settings of drawing texts.\nThe value <i>style</i> 0, 1, 2 and 3 represent "normal", "bold", "italic" and "bold-italic" respectively.
text_size(pt, space, script)	Set font size and other settings of drawing texts.\nFont size can be specified by <i>pt</i>.\nFont-spacing and script-size are specified by the following arguments.
text_obj_get(id, $text)	assign text of the the text object which ID is <i>id</i> to the variable <i>$text</i>.
text_obj_set(id, $text)	set text of the the text object which ID is <i>id</i> as the variable <i>$text</i>.
array_moving_average(dest, src, n, type)	calculate moving average of (<i>n</i> * 2 + 1) sample of the array <i>src</i>\nand set them to the array <i>dest</i>.\nWeighted moving average is used when <i>type</i> is 1.
on_end(proc)	Evaluate <i>proc</i> at the end of plottong the data object.
parameter(id)	Returns the value of the prameter object which ID is <i>id</i>.
mtime()		returns last modification time of the file.
strftime($str, $fmt, t, utc)	convers <i>t</i> (the number of seconds elapsed since the Epoch)\naccording to the format specification <i>$fmt</i>\nand places the result in the string <i>$str</i>.\nWhen <i>utc</i> is true, <i>$str</i> is expressed in Coordinated Universal Time (UTC).
filename($str, basename)	Assign filename of the the data object to the variable <i>$str</i>.\nAny leading directory components are removed when <i>basename</i> is not zero.\nReturn the length of the string <i>$str</i> in characters.
