utils

This module consists of helpful utility functions

electric_emission_cost.utils.convert_utc_to_timezone(utc_hour, timezone_str)[source]

Convert UTC hour (0-23) to the corresponding hour in a specified timezone.

Parameters: utc_hour (int): Hour in UTC (0-23). timezone_str (str): Timezone string, e.g., ‘America/New_York’.

Returns: int: Corresponding hour in the specified timezone.

electric_emission_cost.utils.get_freq_binsize_minutes(freq)[source]

Gets size of a given time frequency expressed in units of minutes

Parameters:

freq (str) – a string of the form [type][freq_binsize], where type corresponds to a numpy.timedelta64 encoding and freq binsize is an integer giving the number of increments of type of one binned increment of our time variable (for example ‘6h’ means the data are grouped into increments of 6 hours)

Raises:

ValueError – when resolution is not minute, hourly, or daily

Returns:

integer giving the number of minutes in the given time frequency unit

Return type:

int

electric_emission_cost.utils.idxparam_value(idx_param)[source]

Returns the parameter value at the given index.

Parameters:

idx_param (pyomo.environ.Param or pyomo.environ.Var) – The Pyomo parameter or variable to be converted

Returns:

Indexed variable or parameter as a numpy array

Return type:

numpy.ndarray

electric_emission_cost.utils.max(expression, model=None, varstr=None)[source]

Elementwise maximum of an expression or array

Parameters:

  • expression ([) – numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Param, pyomo.environ.Var

  • ] – The expression to find the maximum of

  • model (pyomo.environ.Model) – The model object associated with the problem. Only used in the case of Pyomo, so None by default.

  • varstr (str) – Name of the variable to be created if using a Pyomo model

Raises:

TypeError – When expression is not of type numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Param, or pyomo.environ.Var

Returns:

Expression representing max of expression

Return type:

([numpy.Array, cvxpy.Expression, pyomo.environ.Var], pyomo.environ.Model)

electric_emission_cost.utils.max_pos(expression, model=None, varstr=None)[source]

Returns the maximum positive scalar value of an expression. I.e., max([x, 0]) where x is any element of the expression (if a matrix)

Parameters:

  • expression ([) – numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Param, pyomo.environ.Var

  • ] – Expression representing a matrix, vector, or scalar

  • model (pyomo.environ.Model) – The model object associated with the problem. Only used in the case of Pyomo, so None by default.

  • varstr (str) – Name of the variable to be created if using a Pyomo model

Raises:

TypeError – When expression is not of type numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.environ.Param, or pyomo.environ.Var

Returns:

  • ( – [numpy.float, numpy.int, numpy.Array, cvxpy.Expression, or pyomo.environ.Var], pyomo.environ.Model

  • ) – Expression representing maximum positive scalar value of expression

electric_emission_cost.utils.multiply(expression1, expression2, model=None, varstr=None)[source]

Implements elementwise multiplication operation on two optimization expressions

Parameters:

  • expression1 ([) – numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Param, pyomo.environ.Var

  • ] – LHS of multiply operation

  • expression2 ([) – numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Param, pyomo.environ.Var

  • ] – RHS of multiply operation

  • model (pyomo.environ.Model) – The model object associated with the problem. Only used in the case of Pyomo, so None by default.

  • varstr (str) – Name of the variable to be created if using a Pyomo model

Raises:

TypeError – When expression is not of type numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.environ.Param, or pyomo.environ.Var

Returns:

  • [ – numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Expression

  • ] – result from elementwise multiplication of expression1 and expression2

electric_emission_cost.utils.parse_freq(freq)[source]

Parses a time frequency code string, returning its type and its freq_binsize

Parameters:

freq (str) – a string of the form [type][freq_binsize], where type corresponds to a numpy.timedelta64 encoding and freq binsize is an integer giving the number of increments of type of one binned increment of our time variable (for example ‘6h’ means the data are grouped into increments of 6 hours)

Returns:

tuple of the form (int,`str`) giving the binsize and units (freq_type)

Return type:

tuple

electric_emission_cost.utils.sanitize_varstr(varstr)[source]

Sanitizes a variable string by removing non-alphanumeric characters and replacing spaces with underscores.

Parameters:

varstr (str) – The variable string to sanitize.

Returns:

The sanitized variable string.

Return type:

str

electric_emission_cost.utils.sum(expression, axis=0, model=None, varstr=None)[source]

Elementwise maximum of an expression or array

Parameters:

  • expression ([) – numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray, pyomo.environ.Param, pyomo.environ.Var

  • ] – Expression representing a matrix to sum

  • axis (int) – Optional axis along which to compute sum. Default is 0

  • model (pyomo.environ.Model) – The model object associated with the problem. Only used in the case of Pyomo, so None by default.

  • varstr (str) – Name of the variable to be created if using a Pyomo model

Raises:

TypeError – When expression is not of type numpy.Array, cvxpy.Expression, pyomo.core.expr.numeric_expr.NumericExpression, pyomo.core.expr.numeric_expr.NumericNDArray pyomo.environ.Param, or pyomo.environ.Var

Returns:

Expression representing sum of expression along axis

Return type:

[numpy.Array, cvxpy.Expression, pyomo.environ.Expression]