Add math functions (#2609)

* Add sumprod(), frexp(), usclose() functions

* Add tests

Added tests for sumprod(), frexp(), and isclose() functions

* fix an error

* fix an error

* fix an error

* fix errors

* remove sumprod()

* remove empty lines

Co-authored-by: Shaikh Ubaid <[email protected]>

* Add tests

* Update src/runtime/math.py

Co-authored-by: Shaikh Ubaid <[email protected]>

---------

Co-authored-by: Shaikh Ubaid <[email protected]>

Author: farah-salama

integration_tests/test_math.py

@@ -1,8 +1,8 @@
 from math import (factorial, isqrt, perm, comb, degrees, radians, exp, pow,
                   ldexp, fabs, gcd, lcm, floor, ceil, remainder, expm1, fmod, log1p, trunc,
-                  modf, fsum, prod, dist)
+                  modf, fsum, prod, dist, frexp, isclose)
 import math
-from lpython import i32, i64, f32, f64
+from lpython import i8, i16, i32, i64, f32, f64
 
 eps: f64
 eps = 1e-12
@@ -253,6 +253,58 @@ def test_issue_1242():
     assert abs(math.pi - 3.14159265358979323846) < 1e-10
 
 
+def test_frexp():
+    x:f64 = 6.23
+    mantissa:f64
+    exponent:i16
+    mantissa, exponent = frexp(x)
+    assert abs(mantissa - 0.77875) < eps and exponent == i16(3)
+
+    x = 0.8
+    mantissa, exponent = frexp(x)
+    assert abs(mantissa - 0.8) < eps and exponent == i16(0)
+
+    x = 19.74
+    mantissa, exponent = frexp(x)
+    assert abs(mantissa - 0.616875) < eps and exponent == i16(5)
+
+    x = -23.6
+    mantissa, exponent = frexp(x)
+    assert abs(mantissa + 0.7375) < eps and exponent == i16(5)
+
+    y:f32 = f32(1.23)
+    mantissa2:f32
+    exponent2:i8
+    mantissa2, exponent2 = frexp(y)
+    assert abs(mantissa2 - f32(0.615)) < f32(eps) and exponent2 == i8(1)
+
+    y = f32(-1.23)
+    mantissa2, exponent2 = frexp(y)
+    assert abs(mantissa2 - f32(-0.615)) < f32(eps) and exponent2 == i8(1)
+
+
+def test_isclose():
+    x:f64 = 2.2130
+    y:f64 = 2.2129
+    assert isclose(x, y, rel_tol=0.01, abs_tol=0.001)
+    assert isclose(x,y,rel_tol=0.0000001,abs_tol=0.01)
+    assert isclose(x,y,rel_tol=0.1,abs_tol=0.000001)
+    assert not isclose(x,y,rel_tol=0.0000001,abs_tol=0.00001)
+
+    x = -1.265
+    y = 1.265
+    assert not isclose(x,y,rel_tol=0.001,abs_tol=0.0001)
+    assert not isclose(y,x,rel_tol=0.01,abs_tol=0.1)
+    assert not isclose(x,y,rel_tol=0.01,abs_tol=0.1)
+
+    x = -1.2650
+    y = -1.2651
+    assert isclose(x, y, rel_tol=0.01, abs_tol=0.001)
+    assert isclose(x,y,rel_tol=0.0000001,abs_tol=0.01)
+    assert isclose(x,y,rel_tol=0.1,abs_tol=0.000001)
+    assert not isclose(x,y,rel_tol=0.0000001,abs_tol=0.00001)
+
+
 def check():
     test_factorial_1()
     test_comb()
@@ -278,6 +330,8 @@ def check():
     test_dist()
     test_modf()
     test_issue_1242()
+    test_frexp()
+    test_isclose()
 
 
 check()

src/runtime/math.py

@@ -709,3 +709,39 @@ def remainder(x: f64, y: f64) -> f64:
     if x - y*f64(q) > y*f64(q + i64(1)) - x:
         return x - y*f64(q + i64(1))
     return x - y*f64(q)
+
+
+@overload
+def frexp(x:f64) -> tuple[f64,i16]:
+    '''
+    Return the mantissa and exponent of x as the pair (m, e).
+    m is a float and e is an integer such that x == m * 2**e exactly.
+    '''
+    exponent: i16 = i16(0)
+    while f64(fabs(x)) > f64(1.0):
+        exponent += i16(1)
+        x /= 2.0
+    return x, exponent
+
+
+@overload
+def frexp(x:f32) -> tuple[f32,i8]:
+    '''
+    Return the mantissa and exponent of x as the pair (m, e).
+    m is a float and e is an integer such that x == m * 2**e exactly.
+    '''
+    exponent: i8 = i8(0)
+    while f32(fabs(x)) > f32(1.0):
+        exponent += i8(1)
+        x /= f32(2.0)
+    return x, exponent
+
+
+@overload
+def isclose(a:f64, b:f64, rel_tol:f64 = 1e-09, abs_tol:f64 = 0.0) -> bool:
+    '''
+    Return True if the values a and b are close to each other and False otherwise.
+    '''
+    difference:f64 = fabs(a-b)
+    greater:f64 = max(fabs(a),fabs(b))
+    return difference <= max(rel_tol*greater, abs_tol)