Expressions¶
Mathematical expressions in Myokit are represented as trees of
Expression
objects. For example the expression 5 + 2 is represented
as a Plus
expression with two operands of the type
Number
. All expressions extend the Expression
base
class described below.
Creating expression trees manually is a labourintesive process. In most cases, expressions will be created by the parser.

class
myokit.
Expression
(operands=None)¶ Myokit’s most generic interface for expressions. All expressions extend this class.
Expressions are immutable objects.
Expression objects have an
_rbp
property determining their right binding power (myokit uses a topdown operator precedence parsing scheme) and an optional_token
property that may contain the text token this expression object was originally parsed from.Abstract class

bracket
(op=None)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.

code
(component=None)¶ Returns this expression formatted in
mmt
syntax.When
LhsExpressions
are encountered, their full qname is rendered, except in two cases: (1) if the variable’s component matches the argumentcomponent
or (2) if the variable is nested. Aliases are used in place of qnames if found in the given component.

contains_type
(kind)¶ Returns True if this expression tree contains an expression of the given type.

depends_on
(lhs)¶ Returns
True
if thisExpression
depends on the givenLhsExpresion
.Only dependencies appearing directly in the expression are checked.

eval
(subst=None, precision=64)¶ Evaluates this expression and returns the result. This operation will fail if the expression contains any
Names
that do not resolve to numerical values.The optional argument
subst
can be used to pass a dictionary mappingLhsExpression
objects to expressions or numbers to substitute them with.For debugging purposes, the argument
precision
can be set tomyokit.SINGLE_PRECISION
to perform the evaluation with 32 bit floating point numbers.

eval_unit
(mode=1)¶ Evaluates the unit this expression should have, based on the units of its variables and literals.
Incompatible units may result in a
myokit.IncompatibleUnitError
being raised. The method for dealing with unspecified units can be set using themode
argument.Using
myokit.UNIT_STRICT
any unspecified unit will be treated as dimensionless. For example addingNone + [kg]
will be treated as[1] + [kg]
which will raise an error. Similarly,None * [m]
will be taken to mean[1] * [m]
which is valid, andNone * None
will return[1]
. In strict mode, functions such asexp()
, which expect dimensionless input will raise an error if given a nondimensionless operator.Using
myokit.UNIT_TOLERANT
unspecified units will try to be ignored where possible. For example, the expressionNone + [kg]
will be treated as[kg] + [kg]
, whileNone * [m]
will be read as[1] * [m]
andNone * None
will returnNone
. Functions such asexp()
will not raise an error, but simply return a dimensionless value.The method is intended to be used to check the units in a model, so every branch of an expression is evaluated, even if it won’t affect the final result.
In strict mode, this method will always either return a
myokit.Unit
or raise anmyokit.IncompatibleUnitError
. In tolerant mode,None
will be returned if the units are unknown.

is_conditional
()¶ Returns True if and only if this expression’s tree contains a conditional statement.

is_constant
()¶ Returns true if this expression contains no references or only references to variables with a constant value.

is_literal
()¶ Returns
True
if this expression doesn’t contain any references.

is_state_value
()¶ Returns
True
if this expression is aName
pointing to the current value of a state variable.

operator_rep
()¶ Returns a representation of this expression’s type. (For example ‘+’ or ‘*’)

pyfunc
(use_numpy=True)¶ Converts this expression to python and returns the new function’s handle.
By default, when converting mathematical functions such as
log
, the version fromnumpy
(i.e.numpy.log
) is used. To use the builtinmath
module instead, setuse_numpy=False
.

pystr
(use_numpy=False)¶ Returns a string representing this expression in python syntax.
By default, builtin functions such as ‘exp’ are converted to the python version ‘math.exp’. To use the numpy versions, set
numpy=True
.

references
()¶ Returns a set containing all references to variables made in this expression.

tree_str
()¶ Returns a string representing the parse tree corresponding to this expression.

validate
()¶ Validates operands, checks cycles without following references. Will raise exceptions if errors are found.

walk
(allowed_types=None)¶ Returns an iterator over this expression tree (depthfirst). This is a slow operation. Do _not_ use in performance sensitive code!
Example:
5 + (2 * sqrt(x)) 1) Plus 2) Number(5) 3) Multiply 4) Number(2) 5) Sqrt 6) Name(x)
To return only expressions of certain types, pass in a sequence
allowed_typess
, containing all types desired in the output.

Names and numbers¶
The simplest types of expression are atomic expressions, which have either a
definite, numerical value (Number
) or point to a variable
(Name
).
For equations a distinction is made between what may appear on the lefthand
side (lhs) and righthand side (rhs). To indicate this difference in code, all
lefthand side equations must extend the class LhsExpression
.

class
myokit.
Number
(value, unit=None)¶ Represents a number with an optional unit for use in Myokit expressions. All numbers used in Myokit expressions are floating point.
>>> import myokit >>> x = myokit.Number(10) >>> print(x) 10
>>> x = myokit.Number(5.00, myokit.units.V) >>> print(x) 5 [V]
Arguments:
value
 A numerical value (something that can be converted to a
float
). Number objects are immutable so no clone constructor is provided. unit
 A unit to associate with this number. If no unit is specified the number’s unit will be left undefined.
Extends:
Expression

bracket
(op=None)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.

convert
(unit)¶ Returns a copy of this number in a different unit. If the two units are not compatible a
myokit.IncompatibleUnitError
is raised.

is_constant
()¶ Returns true if this expression contains no references or only references to variables with a constant value.

is_literal
()¶ Returns
True
if this expression doesn’t contain any references.

unit
()¶ Returns the unit associated with this number/quantity or
None
if no unit was specified.

class
myokit.
LhsExpression
(operands=None)¶ An expression referring to the lefthand side of an equation.
Running
eval()
on an LhsExpression returns the evaluation of the associated righthand side. This may result in errors if no righthand side is defined. In other words, this will only work if the expression is embedded in a variable’s defining equation.Abstract class, extends:
Expression

is_constant
()¶ Returns true if this expression contains no references or only references to variables with a constant value.

is_literal
()¶ Returns
True
if this expression doesn’t contain any references.

rhs
()¶ Returns the rhs expression equal to this lhs expression.


class
myokit.
Name
(value)¶ Represents a reference to a variable.
Extends:
LhsExpression

bracket
(op=None)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.

is_state_value
()¶ Returns
True
if this expression is aName
pointing to the current value of a state variable.

rhs
()¶ Returns the rhs expression equal to this lhs expression.


class
myokit.
Derivative
(op)¶ Represents a reference to the timederivative of a variable.
Extends:
LhsExpression

bracket
(op)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.

rhs
()¶ Returns the rhs expression equal to this lhs expression.

Operators¶

class
myokit.
PrefixExpression
(op)¶ Base class for prefix expressions: expressions with a single operand.
Abstract class, extends:
Expression

bracket
(op)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.


class
myokit.
InfixExpression
(left, right)¶ Base class for for infix expressions:
<left> operator <right>
.The order of the operands may matter, so that
<left> operator <right>
is not always equal to<right> operator <left>
.Abstract class, extends:
Expression

bracket
(op)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.

Functions¶

class
myokit.
Function
(*ops)¶ Base class for builtin functions.
Functions have a
name
, which must be set to a human readable function name (usually just the function’s.mmt
equivalent) and a list of integers called_nargs
. Each entry in_nargs
specifies a number of arguments for which the function is implemented. For exampleSin
has_nargs=[1]
whileLog
has_nargs=[1,2]
, showing thatLog
can be called with either1
or2
arguments.If errors occur when creating a function, an IntegrityError may be thrown.
Abstract class, extends:
Expression

bracket
(op=None)¶ Checks if the given operand (which should be an operand of this expression) needs brackets around it when writing a mathematical expression.
For example,
5 + 3
will require a bracket when used in a multiplication (e.g.2 * (5 + 3)
), so callingbracket(5 + 3)
on a multiplication will returnTrue
.Alternatively, when used in a function the expression will not require brackets, as the function (e.g.
sin()
) already provides them, so callingbracket(5 + 3)
on a function will return False.

clone
(subst=None, expand=False, retain=None)¶ Clones this expression.
The optional argument
subst
can be used to pass a dictionary mapping expressions to a substitute. Any expression that finds itself listed as a key in the dictionary will return this replacement value instead.The argument
expand
can be set to True to expand all variables other than states. For example, ifx = 5 + 3 * y
andy = z + sqrt(2)
anddot(z) = ...
, cloning x while expanding will yieldx = 5 + 3 * (z + sqrt(2))
. When expanding, all constants are converted to numerical values. To maintain some of the constants, pass in a list of variables or variable names asretain
.Substitution takes precedence over expansion: A call such as
e.clone(subst={x:y}, expand=True) will replace ``x
byy
but not expand any names appearing iny
.

Conditions¶

class
myokit.
Condition
¶ Abstract class
Interface for conditional expressions that can be evaluated to True or False. Doesn’t add any methods but simply indicates that this is a condition.

class
myokit.
PrefixCondition
(op)¶ Interface for prefix conditions.
Abstract class, extends:
Condition
,PrefixExpression

class
myokit.
InfixCondition
(left, right)¶ Base class for infix expressions.
Abstract class, extends:
Condition
,InfixExpression
Unary plus and minus¶

class
myokit.
PrefixPlus
(op)¶ Prefixed plus. Indicates a positive number
+op
.>>> from myokit import * >>> x = PrefixPlus(Number(10)) >>> print(x.eval()) 10.0
Extends:
PrefixExpression

class
myokit.
PrefixMinus
(op)¶ Prefixed minus. Indicates a negative number
op
.>>> from myokit import * >>> x = PrefixMinus(Number(10)) >>> print(x.eval()) 10.0
Extends:
PrefixExpression
Addition and multiplication¶

class
myokit.
Plus
(left, right)¶ Represents the addition of two operands:
left + right
.>>> from myokit import * >>> x = parse_expression('5 + 2') >>> print(x.eval()) 7.0
Extends:
InfixExpression

class
myokit.
Minus
(left, right)¶ Represents subtraction:
left  right
.>>> from myokit import * >>> x = parse_expression('5  2') >>> print(x.eval()) 3.0
Extends:
InfixExpression

class
myokit.
Multiply
(left, right)¶ Represents multiplication:
left * right
.>>> from myokit import * >>> x = parse_expression('5 * 2') >>> print(x.eval()) 10.0
Extends:
InfixExpression

class
myokit.
Divide
(left, right)¶ Represents division:
left / right
.>>> from myokit import * >>> x = parse_expression('5 / 2') >>> print(x.eval()) 2.5
Extends:
InfixExpression
Powers and roots¶

class
myokit.
Power
(left, right)¶ Represents exponentiation:
left ^ right
.>>> import myokit >>> x = myokit.parse_expression('5 ^ 2') >>> print(x.eval()) 25.0
Extends:
InfixExpression
Logarithms and e¶

class
myokit.
Exp
(*ops)¶ Represents a power of e. Written
exp(x)
in.mmt
syntax.>>> from myokit import * >>> x = Exp(Number(1)) >>> print(round(x.eval(), 4)) 2.7183
Extends:
UnaryDimensionlessFunction

class
myokit.
Log
(*ops)¶ With one argument
log(x)
represents the natural logarithm. With two argumentslog(x, k)
is taken to be the basek
logarithm ofx
.>>> from myokit import * >>> x = Log(Number(10)) >>> print(round(x.eval(), 4)) 2.3026 >>> x = Log(Exp(Number(10))) >>> print(round(x.eval(), 1)) 10.0 >>> x = Log(Number(256), Number(2)) >>> print(round(x.eval(), 1)) 8.0
Extends:
Function

class
myokit.
Log10
(*ops)¶ Represents the base10 logarithm
log10(x)
.>>> from myokit import * >>> x = Log10(Number(100)) >>> print(round(x.eval(), 1)) 2.0
Extends:
UnaryDimensionlessFunction
Trigonometric functions¶
All trigonometric functions use angles in radians.

class
myokit.
Sin
(*ops)¶ Represents the sine function
sin(x)
.>>> from myokit import * >>> x = parse_expression('sin(0)') >>> print(round(x.eval(), 1)) 0.0 >>> x = Sin(Number(3.1415 / 2.0)) >>> print(round(x.eval(), 1)) 1.0
Extends:
UnaryDimensionlessFunction

class
myokit.
Cos
(*ops)¶ Represents the cosine function
cos(x)
.>>> from myokit import * >>> x = Cos(Number(0)) >>> print(round(x.eval(), 1)) 1.0 >>> x = Cos(Number(3.1415 / 2.0)) >>> print(round(x.eval(), 1)) 0.0
Extends:
UnaryDimensionlessFunction

class
myokit.
Tan
(*ops)¶ Represents the tangent function
tan(x)
.>>> from myokit import * >>> x = Tan(Number(3.1415 / 4.0)) >>> print(round(x.eval(), 1)) 1.0
Extends:
UnaryDimensionlessFunction

class
myokit.
ASin
(*ops)¶ Represents the inverse sine function
asin(x)
.>>> from myokit import * >>> x = ASin(Sin(Number(1))) >>> print(round(x.eval(), 1)) 1.0
Extends:
UnaryDimensionlessFunction

class
myokit.
ACos
(*ops)¶ Represents the inverse cosine
acos(x)
.>>> from myokit import * >>> x = ACos(Cos(Number(3))) >>> print(round(x.eval(), 1)) 3.0
Extends:
UnaryDimensionlessFunction

class
myokit.
ATan
(*ops)¶ Represents the inverse tangent function
atan(x)
.>>> from myokit import * >>> x = ATan(Tan(Number(1))) >>> print(round(x.eval(), 1)) 1.0
If two arguments are given they are interpreted as the coordinates of a point (x, y) and the function returns this point’s angle with the (positive) xaxis. In this case, the returned value will be in the range (pi, pi].
Extends:
UnaryDimensionlessFunction
Conditional operators¶

class
myokit.
If
(i, t, e)¶ Allows conditional functions to be defined using an ifthenelse structure.
The first argument to an
If
function must be a condition, followed directly by an expression to use to calculate the function’s return value if this condition isTrue
. The third and final argument specifies the expression’s value if the condition isFalse
.A simple example in
.mmt
syntax:x = if(V < 10, 5 * V + 100, 6 * V)
Extends:
Function

condition
()¶ Returns this iffunction’s condition.

is_conditional
()¶ Returns True if and only if this expression’s tree contains a conditional statement.

piecewise
()¶ Returns an equivalent
Piecewise
object.

value
(which)¶ Returns the expression used when this if’s condition is
True
when called withwhich=True
. Otherwise return the expression used when this if’s condition isFalse
.


class
myokit.
Piecewise
(*ops)¶ Allows piecewise functions to be defined.
The first argument to a
Piecewise
function must be a condition, followed directly by an expression to use to calculate the function’s return value if this condition is true.Any number of conditionexpression pairs can be added. If multiple conditions evaluate as true, only the first one will be used to set the return value.
The final argument should be a default expression to use if none of the conditions evaluate to True. This means the
piecewise()
function can have any odd number of arguments greater than 2.A simple example in
mmt
syntax:x = piecewise( V < 10, 5 * V + 100 V < 20, 6 * V, 7 * V)
This will return
5 * V + 100
for any value smaller than 10,6 * V
for any value greater or equal to 10 but smaller than 20, and7 * V
for any values greather than or equal to 20.Extends:
Function

conditions
()¶ Returns an iterator over the conditions used by this Piecewise.

is_conditional
()¶ Returns True if and only if this expression’s tree contains a conditional statement.

pieces
()¶ Returns an iterator over the pieces in this Piecewise.


class
myokit.
Not
(op)¶ Negates a condition. Written as
not x
.>>> from myokit import * >>> x = parse_expression('1 == 1') >>> print(x.eval()) True >>> y = Not(x) >>> print(y.eval()) False >>> x = parse_expression('(2 == 2) and not (1 > 2)') >>> print(x.eval()) True
Extends:
PrefixCondition

class
myokit.
Equal
(left, right)¶ Represents an equality check
x == y
.>>> from myokit import * >>> print(parse_expression('1 == 0').eval()) False >>> print(parse_expression('1 == 1').eval()) True
Extends:
InfixCondition

class
myokit.
NotEqual
(left, right)¶ Represents an inequality check
x != y
.>>> from myokit import * >>> print(parse_expression('1 != 0').eval()) True >>> print(parse_expression('1 != 1').eval()) False
Extends:
InfixCondition

class
myokit.
More
(left, right)¶ Represents an ismorethan check
x > y
.>>> from myokit import * >>> print(parse_expression('5 > 2').eval()) True
Extends:
InfixCondition

class
myokit.
Less
(left, right)¶ Represents an islessthan check
x < y
.>>> from myokit import * >>> print(parse_expression('5 < 2').eval()) False
Extends:
InfixCondition

class
myokit.
MoreEqual
(left, right)¶ Represents an ismorethanorequal check
x > y
.>>> from myokit import * >>> print(parse_expression('2 >= 2').eval()) True
Extends:
InfixCondition

class
myokit.
LessEqual
(left, right)¶ Represents an islessthanorequal check
x <= y
.>>> from myokit import * >>> print(parse_expression('2 <= 2').eval()) True
Extends:
InfixCondition

class
myokit.
And
(left, right)¶ True if two conditions are true:
x and y
.>>> from myokit import * >>> print(parse_expression('1 == 1 and 2 == 4').eval()) False >>> print(parse_expression('1 == 1 and 4 == 4').eval()) True
Extends:
InfixCondition

class
myokit.
Or
(left, right)¶ True if at least one of two conditions is true:
x or y
.>>> from myokit import * >>> print(parse_expression('1 == 1 or 2 == 4').eval()) True
Extends:
InfixCondition
Miscellaneous¶

class
myokit.
Abs
(*ops)¶ Returns the absolute value of a number
abs(x)
.>>> from myokit import * >>> x = parse_expression('abs(5)') >>> print(x.eval()) 5.0 >>> x = parse_expression('abs(5)') >>> print(x.eval()) 5.0
Extends:
Function

class
myokit.
Floor
(*ops)¶ Represents a rounding towards minus infinity
floor(x)
.>>> from myokit import * >>> x = Floor(Number(5.2)) >>> print(x.eval()) 5.0 >>> x = Floor(Number(5.2)) >>> print(x.eval()) 6.0
Extends:
Function

class
myokit.
Ceil
(*ops)¶ Represents a rounding towards positve infinity
ceil(x)
.>>> from myokit import * >>> x = Ceil(Number(5.2)) >>> print(x.eval()) 6.0 >>> x = Ceil(Number(5.2)) >>> print(x.eval()) 5.0
Extends:
Function

class
myokit.
Quotient
(left, right)¶ Represents the quotient (integer division) of a division
left // right
.>>> import myokit >>> x = myokit.parse_expression('7 // 3') >>> print(x.eval()) 2.0
Note that, for negative numbers Myokit follows the convention of Python (and some other languages, but not e.g. C) of rounding towards negative infinity, rather than towards zero. Thus:
>>> print(myokit.parse_expression('7 // 3').eval()) 3.0
Similarly:
>>> print(myokit.parse_expression('5 // 3').eval()) 2.0
See: https://pythonhistory.blogspot.co.uk/2010/08/ And: https://en.wikipedia.org/wiki/Modulo_operation
Extends:
InfixExpression

class
myokit.
Remainder
(left, right)¶ Represents the remainder of a division (the “modulo”), expressed in
mmt
syntax asleft % right
.>>> import myokit >>> x = myokit.parse_expression('7 % 3') >>> print(x.eval()) 1.0
Note that, for negative numbers Myokit follows the convention of Python that the quotient is rounded to negative infinity. Thus:
>>> print(myokit.parse_expression('7 // 3').eval()) 3.0
and therefore:
>>> print(myokit.parse_expression('7 % 3').eval()) 2.0
Similarly:
>>> print(myokit.parse_expression('5 // 3').eval()) 2.0
so that:
>>> print(myokit.parse_expression('5 % 3').eval()) 1.0
Extends:
InfixExpression

class
myokit.
UserFunction
(name, arguments, template)¶ Defines a user function. User functions are not
Expression
objects, but template expressions that are converted upon parsing. They allow common functions (for example a boltzman function) to be used in string expressions.Arguments:
name
 The user function’s name (a string)
arguments
 A list of function argument names (all of type
Name
) template
 The
Expression
evaluating this function.

arguments
()¶ Returns an iterator over this user function’s arguments.

convert
(arguments)¶ Returns an
Expression
object, evaluated using the given dictionary mapping argument Name objects to expressions.