# Math functions: tests sqrt(), log(), sin() etc and also getarg()
# Also uses real arrays
# invoke as "a.out 3.14159 6.28319 9.42478"

resource realarr()

    real REL_ERR = 1e-5 # allowed relative error, [was] implicit declaration
    procedure fuzrcmp(real r1, real r2)  returns bool   result {
	# if one wants to get an idea of the relative error print ...
	# write(r1, r2, abs((r1-r2)/r2))
	if (abs((r1 - r2)/r1) < REL_ERR) { result = true ;
	} else { result = false;
	}
    }

    # getarg() reals
    real r = 2*1 + 2*555.e1  # [was] implicit declaration of a real var


    getarg(1, r)
    write(fuzrcmp(r, 3141.59265e-3))

    getarg(2, r)

    bool result = fuzrcmp(r, 2*3141592.65e-6) # [was] implicit decl of a bool
    write(result)

    getarg(3, r)
    result = fuzrcmp(r, 3*.314159265e+1)
    write(result)

    # read() reals
    real  stdrarr [2 : 12] 

    procedure cmp_1d_rarr(string[*] s, real rarr [2:12])  {
	for [ i = lb(rarr) to ub(rarr) ] {
		result = fuzrcmp(rarr[i], stdrarr[i])
		if (not result) { write("error in ", s) }
	}
    }

    real  rarr [2 : 12] 

    # tests log()
    for [ i = lb(rarr) to ub(rarr) ] { rarr[i] = log(i) }
    for [ i = lb(stdrarr) to ub(stdrarr) ] { read(stdrarr[i]) }
    cmp_1d_rarr("log()", rarr)

    # tests sqrt()
    for [ i = lb(rarr) to ub(rarr) ] { rarr[i] = sqrt(i) }
    for [ i = lb(stdrarr) to ub(stdrarr) ] { read(stdrarr[i]) }
    cmp_1d_rarr("sqrt()", rarr)

    # tests sin(), cos(), tan()
    for [ i = lb(rarr) to ub(rarr) ] { rarr[i] = sin(i) }
    for [ i = lb(stdrarr) to ub(stdrarr) ] { read(stdrarr[i]) }
    cmp_1d_rarr("sin()", rarr)

    for [ i = lb(rarr) to ub(rarr) ] { rarr[i] = cos(i) }
    for [ i = lb(stdrarr) to ub(stdrarr) ] { read(stdrarr[i]) }
    cmp_1d_rarr("cos()", rarr)


    for [ i = lb(rarr) to ub(rarr) ] { rarr[i] = tan(i) }
    for [ i = lb(stdrarr) to ub(stdrarr) ] { read(stdrarr[i]) }
    cmp_1d_rarr("tan()", rarr)


    # sin, cos
    if (not fuzrcmp(sin(3.141592/2), sin(30)*sin(30) + cos(30)*cos(30))) {
	write("sin^2 30 + cos^2 30 is not equal to one")
    }
    if (not fuzrcmp(tan(30), sin(30) / cos(30))) {
	write("sin 30 / cos 30 is not equal to tan(30)")
    }
end realarr