Source code for shape_generator.helpers

from sympy import Expr, sqrt, Symbol, solve, Float
from pandas import read_csv, DataFrame
import pandas
import sympy
from io import StringIO
from os import path, listdir, remove
from math import radians, cos, tan

# these variables are used to solve symbolic mathematical equations
# x is the control variable over the height ... max(x) = H_cross_section
x = Symbol('x', real=True, positive=True)
d = Symbol('d', real=True)  # interception of the linear function


def csv(txt, comment=None):
    """
    Read the string in txt as csv file and return the content as DataFrame.

    Args:
        txt (str): content of csv
        comment (str): comment sign

    Returns:
        pandas.DataFrame: csv table as pandas DataFrame
    """
    df = read_csv(StringIO(txt), index_col=0, skipinitialspace=True, skip_blank_lines=True, comment=comment)
    df = df[df.index.notnull()].copy()
    df.index = df.index.astype(str)
    return df


def deg2slope(degree):
    """
    convert degrees to a slope (:math:`\\Delta x / \\Delta y`)

    Args:
        degree (float): angle in degree

    Returns:
        float: slope

    .. figure:: images/slope.gif
        :align: center
        :alt: slope
        :figclass: align-center

        Slope
    """
    return round(tan(radians(degree)), 5)


def channel_end(r, end_degree):
    """
    get vertical end of the channel based on the radius of the channel and an end angle

    Args:
        r (float): radius of the channel
        end_degree (float): end angle in degree (°)

    Returns:
        float: height of the channel when the circle reaches a certain angle

    .. figure:: images/channel_end.gif
        :align: center
        :alt: channel end
        :figclass: align-center

        Channel end
    """
    return r * (1 - cos(radians(end_degree)))


def circle(r, x_m=0, y_m=0, clockwise=False):
    """
    get function/expression of a circle with a given mid point

    Args:
        r (float): radius
        x_m (float): x axis value of the mid point
        y_m (float): y axis value of the mid point
        clockwise (bool): whether the circle is clockwise or anticlockwise

    Returns:
        sympy.core.expr.Expr: function of the circle

    .. figure:: images/kreis.gif
        :align: center
        :alt: circle
        :figclass: align-center

        Circle
    """
    return sqrt(Float(float(r)) ** 2 - (x - Float(float(x_m))) ** 2) * (-1 if clockwise else 1) + Float(float(y_m))


def linear(slope, p0):
    """
    get function/expression of a straight line with a given point which it intercepts

    Args:
        slope (float): slope
        p0 (set[float, float]): point as a set of a x and a y coordinate

    Returns:
        sympy.core.expr.Expr: linear function

    .. figure:: images/gerade.gif
        :align: center
        :alt: straight line
        :figclass: align-center

        Straight line
    """
    x0, y0 = p0
    if slope == 0:
        return x0
    fi = (x - d) / slope
    di = solve(fi.subs(x, x0) - y0, d)[0]
    fi = fi.subs(d, di)
    return fi


def combine_input_files(shape_path, delete_original=False):
    """combine all generated shape text files to a single inp-like text file

    When running the :func:`shape_generator.shape_generator.Profile.input_file` function, a .txt file will be created.
    Those txt files will be combines to a single file with this function.
    This makes it easier to import all shapes to the .inp file.

    Args:
        shape_path (str): path where the shapes are stored
        delete_original (bool): whether to delete the original single files
    """
    with open(path.join(shape_path, 'all_shapes.txt'), 'w') as outfile:
        for fname in listdir(shape_path):
            if not fname.endswith('_shape.txt'):
                continue
            in_fn = path.join(shape_path, fname)
            with open(in_fn) as infile:
                outfile.write('\n')
                outfile.write(infile.read())
            if delete_original:
                remove(in_fn)
    print('Files are combined and originals {}deleted.'.format('' if delete_original else 'NOT '))