def test_Print():
fmt = "%d %.3f"
ps = Print([n, x], fmt)
assert str(ps.format_string) == fmt
assert ps.print_args == Tuple(n, x)
assert ps.args == (Tuple(n, x), QuotedString(fmt), none)
assert ps == Print((n, x), fmt)
assert ps != Print([x, n], fmt)
assert ps.func(*ps.args) == ps
ps2 = Print([n, x])
assert ps2 == Print([n, x])
assert ps2 != ps
assert ps2.format_string == None
def test_ccode_codegen_ast():
assert ccode(Comment("this is a comment")) == "// this is a comment"
assert ccode(While(abs(x) > 1,
[aug_assign(x, '-', 1)])) == ('while (fabs(x) > 1) {\n'
' x -= 1;\n'
'}')
assert ccode(Scope([AddAugmentedAssignment(x, 1)])) == ('{\n'
' x += 1;\n'
'}')
inp_x = Declaration(Variable(x, type=real))
assert ccode(FunctionPrototype(real, 'pwer',
[inp_x])) == 'double pwer(double x)'
assert ccode(
FunctionDefinition(
real, 'pwer', [inp_x],
[Assignment(x, x**2)])) == ('double pwer(double x){\n'
' x = pow(x, 2);\n'
'}')
# Elements of CodeBlock are formatted as statements:
block = CodeBlock(
x,
Print([x, y], "%d %d"),
FunctionCall('pwer', [x]),
Return(x),
)
assert ccode(block) == '\n'.join([
'x;',
'printf("%d %d", x, y);',
'pwer(x);',
'return x;',
])
def test_standard():
ast = Print("x y".split(), "coordinate: %12.5g %12.5g")
assert (render_as_module(ast, standard="python3") ==
'\n\nprint("coordinate: %12.5g %12.5g" % (x, y))')
assert (render_as_module(
ast,
standard="python2") == '\n\nprint "coordinate: %12.5g %12.5g" % (x, y)'
)
def test_Program():
x = Symbol('x', real=True)
vx = Variable.deduced(x, 42)
decl = Declaration(vx)
prnt = Print([x, x+1])
prog = Program('foo', [decl, prnt])
if not has_fortran():
skip("No fortran compiler found.")
(stdout, stderr), info = compile_run_strings([('main.f90', fcode(prog, standard=90))], clean=True)
assert '42' in stdout
assert '43' in stdout
assert stderr == ''
assert info['exit_status'] == os.EX_OK
def test_Program():
x = Symbol("x", real=True)
vx = Variable.deduced(x, 42)
decl = Declaration(vx)
prnt = Print([x, x + 1])
prog = Program("foo", [decl, prnt])
if not has_fortran():
skip("No fortran compiler found.")
(stdout, stderr), info = compile_run_strings(
[("main.f90", fcode(prog, standard=90))], clean=True)
assert "42" in stdout
assert "43" in stdout
assert stderr == ""
assert info["exit_status"] == os.EX_OK
def test_Print():
fmt = "%d %.3f"
ps = Print([n, x], fmt)
assert str(ps.format_string) == fmt
assert ps.print_args == Tuple(n, x)
assert ps.args == (Tuple(n, x), QuotedString(fmt), none)
assert ps == Print((n, x), fmt)
assert ps != Print([x, n], fmt)
assert ps.func(*ps.args) == ps
ps2 = Print([n, x])
assert ps2 == Print([n, x])
assert ps2 != ps
assert ps2.format_string == None
def test_ccode_codegen_ast():
assert ccode(Comment("this is a comment")) == "// this is a comment"
assert ccode(While(abs(x) > 1, [aug_assign(x, "-", 1)])) == (
"while (fabs(x) > 1) {\n" " x -= 1;\n" "}"
)
assert ccode(Scope([AddAugmentedAssignment(x, 1)])) == ("{\n" " x += 1;\n" "}")
inp_x = Declaration(Variable(x, type=real))
assert ccode(FunctionPrototype(real, "pwer", [inp_x])) == "double pwer(double x)"
assert ccode(
FunctionDefinition(real, "pwer", [inp_x], [Assignment(x, x ** 2)])
) == ("double pwer(double x){\n" " x = pow(x, 2);\n" "}")
# Elements of CodeBlock are formatted as statements:
block = CodeBlock(x, Print([x, y], "%d %d"), FunctionCall("pwer", [x]), Return(x),)
assert ccode(block) == "\n".join(
["x;", 'printf("%d %d", x, y);', "pwer(x);", "return x;",]
)
def test_Subroutine():
# Code to generate the subroutine in the example from
# http://www.fortran90.org/src/best-practices.html#arrays
r = Symbol("r", real=True)
i = Symbol("i", integer=True)
v_r = Variable.deduced(r, attrs=(dimension(assumed_extent), intent_out))
v_i = Variable.deduced(i)
v_n = Variable("n", integer)
do_loop = Do([Assignment(Element(r, [i]),
literal_dp(1) / i**2)], i, 1, v_n)
sub = Subroutine(
"f",
[v_r],
[
Declaration(v_n),
Declaration(v_i),
Assignment(v_n, size(r)), do_loop
],
)
x = Symbol("x", real=True)
v_x3 = Variable.deduced(x, attrs=[dimension(3)])
mod = Module("mymod", definitions=[sub])
prog = Program(
"foo",
[
use(mod, only=[sub]),
Declaration(v_x3),
SubroutineCall(sub, [v_x3]),
Print([sum_(v_x3), v_x3]),
],
)
if not has_fortran():
skip("No fortran compiler found.")
(stdout, stderr), info = compile_run_strings(
[("a.f90", fcode(mod, standard=90)),
("b.f90", fcode(prog, standard=90))],
clean=True,
)
ref = [1.0 / i**2 for i in range(1, 4)]
assert str(sum(ref))[:-3] in stdout
for _ in ref:
assert str(_)[:-3] in stdout
assert stderr == ""
def test_Module():
x = Symbol('x', real=True)
v_x = Variable.deduced(x)
sq = FunctionDefinition(real, 'sqr', [v_x], [Return(x**2)])
mod_sq = Module('mod_sq', [], [sq])
sq_call = FunctionCall('sqr', [42.])
prg_sq = Program(
'foobar',
[use('mod_sq', only=['sqr']),
Print(['"Square of 42 = "', sq_call])])
if not has_fortran():
skip("No fortran compiler found.")
(stdout, stderr), info = compile_run_strings(
[('mod_sq.f90', fcode(mod_sq, standard=90)),
('main.f90', fcode(prg_sq, standard=90))],
clean=True)
assert '42' in stdout
assert str(42**2) in stdout
assert stderr == ''
def test_ImpliedDoLoop():
if not has_fortran():
skip("No fortran compiler found.")
a, i = symbols('a i', integer=True)
idl = ImpliedDoLoop(i**3, i, -3, 3, 2)
ac = ArrayConstructor([-28, idl, 28])
a = array(a, dim=[':'], attrs=[allocatable])
prog = Program(
'idlprog',
[a.as_Declaration(), Assignment(a, ac),
Print([a])])
fsrc = fcode(prog, standard=2003, source_format='free')
(stdout, stderr), info = compile_run_strings([('main.f90', fsrc)],
clean=True)
for numstr in '-28 -27 -1 1 27 28'.split():
assert numstr in stdout
assert stderr == ''
assert info['exit_status'] == os.EX_OK
def test_Module():
x = Symbol("x", real=True)
v_x = Variable.deduced(x)
sq = FunctionDefinition(real, "sqr", [v_x], [Return(x**2)])
mod_sq = Module("mod_sq", [], [sq])
sq_call = FunctionCall("sqr", [42.0])
prg_sq = Program(
"foobar",
[use("mod_sq", only=["sqr"]),
Print(['"Square of 42 = "', sq_call])])
if not has_fortran():
skip("No fortran compiler found.")
(stdout, stderr), info = compile_run_strings(
[
("mod_sq.f90", fcode(mod_sq, standard=90)),
("main.f90", fcode(prg_sq, standard=90)),
],
clean=True,
)
assert "42" in stdout
assert str(42**2) in stdout
assert stderr == ""
def test_ccode_codegen_ast():
# Note that C only allows comments of the form /* ... */, double forward
# slash is not standard C, and some C compilers will grind to a halt upon
# encountering them.
assert ccode(
Comment("this is a comment")) == "/* this is a comment */" # not //
assert ccode(While(abs(x) > 1,
[aug_assign(x, '-', 1)])) == ('while (fabs(x) > 1) {\n'
' x -= 1;\n'
'}')
assert ccode(Scope([AddAugmentedAssignment(x, 1)])) == ('{\n'
' x += 1;\n'
'}')
inp_x = Declaration(Variable(x, type=real))
assert ccode(FunctionPrototype(real, 'pwer',
[inp_x])) == 'double pwer(double x)'
assert ccode(
FunctionDefinition(
real, 'pwer', [inp_x],
[Assignment(x, x**2)])) == ('double pwer(double x){\n'
' x = pow(x, 2);\n'
'}')
# Elements of CodeBlock are formatted as statements:
block = CodeBlock(
x,
Print([x, y], "%d %d"),
FunctionCall('pwer', [x]),
Return(x),
)
assert ccode(block) == '\n'.join([
'x;',
'printf("%d %d", x, y);',
'pwer(x);',
'return x;',
])
def newtons_method(expr,
wrt,
atol=1e-12,
delta=None,
debug=False,
itermax=None,
counter=None):
""" Generates an AST for Newton-Raphson method (a root-finding algorithm).
Returns an abstract syntax tree (AST) based on ``sympy.codegen.ast`` for Netwon's
method of root-finding.
Parameters
==========
expr : expression
wrt : Symbol
With respect to, i.e. what is the variable.
atol : number or expr
Absolute tolerance (stopping criterion)
delta : Symbol
Will be a ``Dummy`` if ``None``.
debug : bool
Whether to print convergence information during iterations
itermax : number or expr
Maximum number of iterations.
counter : Symbol
Will be a ``Dummy`` if ``None``.
Examples
========
>>> from sympy import symbols, cos
>>> from sympy.codegen.ast import Assignment
>>> from sympy.codegen.algorithms import newtons_method
>>> x, dx, atol = symbols('x dx atol')
>>> expr = cos(x) - x**3
>>> algo = newtons_method(expr, x, atol, dx)
>>> algo.has(Assignment(dx, -expr/expr.diff(x)))
True
References
==========
.. [1] https://en.wikipedia.org/wiki/Newton%27s_method
"""
if delta is None:
delta = Dummy()
Wrapper = Scope
name_d = 'delta'
else:
Wrapper = lambda x: x
name_d = delta.name
delta_expr = -expr / expr.diff(wrt)
whl_bdy = [
Assignment(delta, delta_expr),
AddAugmentedAssignment(wrt, delta)
]
if debug:
prnt = Print([wrt, delta],
r"{}=%12.5g {}=%12.5g\n".format(wrt.name, name_d))
whl_bdy = [whl_bdy[0], prnt] + whl_bdy[1:]
req = Gt(Abs(delta), atol)
declars = [Declaration(Variable(delta, type=real, value=oo))]
if itermax is not None:
counter = counter or Dummy(integer=True)
v_counter = Variable.deduced(counter, 0)
declars.append(Declaration(v_counter))
whl_bdy.append(AddAugmentedAssignment(counter, 1))
req = And(req, Lt(counter, itermax))
whl = While(req, CodeBlock(*whl_bdy))
blck = declars + [whl]
return Wrapper(CodeBlock(*blck))
def test_standard():
ast = Print('x y'.split(), "coordinate: %12.5g %12.5g")
assert render_as_module(ast, standard='python3') == \
'\n\nprint("coordinate: %12.5g %12.5g" % (x, y))'
assert render_as_module(ast, standard='python2') == \
'\n\nprint "coordinate: %12.5g %12.5g" % (x, y)'