Search references for HEAVISIDE STEP-FUNCTION. Phrases containing HEAVISIDE STEP-FUNCTION
See searches and references containing HEAVISIDE STEP-FUNCTION!HEAVISIDE STEP-FUNCTION
Indicator function of positive numbers
The Heaviside step function, or the unit step function, usually denoted by H or θ (but sometimes u, 1 or 𝟙), is a step function named after Oliver Heaviside
Heaviside_step_function
Linear combination of indicator functions of real intervals
Piecewise Sigmoid function Simple function Step detection Heaviside step function Piecewise-constant valuation "Step Function". "Step Functions - Mathonline"
Step_function
Mathematical function having a characteristic S-shaped curve or sigmoid curve
There is also the Heaviside step function, which instantaneously transitions between 0 and 1. A wide variety of sigmoid functions including the logistic
Sigmoid_function
Time behavior of a system controlled by Heaviside step functions
step response of a system in a given initial state consists of the time evolution of its outputs when its control inputs are Heaviside step functions
Step_response
System in quantum mechanics
equation for a particle with a step-like potential in one dimension. Typically, the potential is modeled as a Heaviside step function. The time-independent Schrödinger
Step_potential
Generalized function whose value is zero everywhere except at zero
it is the distributional derivative of the Heaviside step function. This means that for every test function φ, one has δ [ φ ] = − ∫ − ∞ ∞ φ ′ ( x ) H
Dirac_delta_function
Function returning minus 1, zero or plus 1
value Heaviside step function Negative number Rectangular function Sigmoid function (Hard sigmoid) Step function (Piecewise constant function) Three-way
Sign_function
Type of feedforward neural network
separable data. A perceptron traditionally used a Heaviside step function as its nonlinear activation function. However, the backpropagation algorithm requires
Multilayer_perceptron
Piecewise function that clamps its input to be non-negative
the Heaviside step function with itself: R ( x ) := H ( x ) ∗ H ( x ) {\displaystyle R\left(x\right):=H(x)*H(x)} The integral of the Heaviside step function:
Ramp_function
Integral transform useful in probability theory, physics, and engineering
transform, where the definition of the function being transformed includes being multiplied by the Heaviside step function. The bilateral Laplace transform
Laplace_transform
Mathematical function characterizing set membership
Free variables and bound variables Heaviside step function Identity function Iverson bracket Kronecker delta, a function that can be viewed as an indicator
Indicator_function
{\displaystyle f(t-a)u(t-a)} , where u {\displaystyle u} is the Heaviside step function, is e − a s F ( s ) {\displaystyle e^{-as}F(s)} . The Laplace transform
List_of_Laplace_transforms
British mathematician and electrical engineer (1850–1925)
Oliver Heaviside (/ˈhɛvisaɪd/ HEV-ee-syde; 18 May 1850 – 3 February 1925) was a British mathematician and electrical engineer who invented a new technique
Oliver_Heaviside
Mathematical function resembling a boxcar
b] and H ( x ) {\displaystyle H(x)} is the Heaviside step function. As with most such discontinuous functions, there is a question of the value at the transition
Boxcar_function
Method of solution to differential equations
the Heaviside step function, J ν ( z ) {\textstyle J_{\nu }(z)} is a Bessel function, I ν ( z ) {\textstyle I_{\nu }(z)} is a modified Bessel function of
Green's_function
Artificial neural network node function
)=U(a+\mathbf {v} '\mathbf {b} )} , where U {\displaystyle U} is the Heaviside step function. If a line has a positive slope, on the other hand, it may reflect
Activation_function
Eighth letter of the Greek alphabet
in economic models The ordinal collapsing function developed by Solomon Feferman The Heaviside step function In pharmacology, the fraction of ligand bound
Theta
Mathematical function conceived as a crude model
net" in the brain. As an activation function, it employed a threshold, equivalent to using the Heaviside step function. Initially, only a simple model was
Artificial_neuron
Binary feedback controller
common residential thermostats are bang–bang controllers. The Heaviside step function in its discrete form is an example of a bang–bang control signal
Bang–bang_control
Resistive and inductive circuit
(t)-{\frac {1}{\tau }}e^{-{\frac {t}{\tau }}}u(t)\,,} where u(t) is the Heaviside step function and τ = L/R is the time constant. Similarly, the impulse response
RL_circuit
Partial differential equation in mathematical finance
0\}}-1)=K\left(e^{x}-1\right)H(x),} where H(x) is the Heaviside step function. The Heaviside function corresponds to enforcement of the boundary data in
Black–Scholes_equation
Probability distribution
probability density functions. The cumulative distribution function of such a random variable is then the Heaviside step function translated by the mean
Normal_distribution
S-shaped curve
(with scaling) is a smooth approximation of the Heaviside step function. The standard logistic function is analytic on the whole real line since f : R
Logistic_function
Class of discontinuous functions
δ(x) is also called the unit doublet. The function H ( x ) {\displaystyle H(x)} is the Heaviside step function: H(x) = 0 for x < 0 and H(x) = 1 for x >
Singularity_function
Smoothed ramp function
The logistic function or the sigmoid function is a smooth approximation of the rectifier, the Heaviside step function. The multivariable generalization of
Softplus
Function whose graph is 0, then 1, then 0 again, in an almost-everywhere continuous way
The rectangular function (also known as the rectangle function, rect function, Pi function, Heaviside Pi function, gate function, unit pulse, or the normalized
Rectangular_function
Behavior of structures subjected to time-varying loading
displacement) and x is the displacement. If the loading F(t) is a Heaviside step function (the sudden application of a constant load), the solution to the
Structural_dynamics
Oscillatory error in Fourier series
sinc function: the oscillations in the sinc function cause the ripples in the output. In the case of convolving with a Heaviside step function, the resulting
Gibbs_phenomenon
Sigmoid shape special function
functions occur, for example, in solutions of the heat equation when boundary conditions are given by the Heaviside step function. The error function
Error_function
Type of activation function
the logistic function. This in turn can be viewed as a smooth approximation of the derivative of the rectifier, the Heaviside step function. The multivariable
Rectified_linear_unit
Type of non-sinusoidal waveform
square wave can also be defined with respect to the Heaviside step function u(t) or the rectangular function Π(t): x ( t ) = 2 [ ∑ n = − ∞ ∞ Π ( 2 ( t − n T
Square_wave_(waveform)
Concept in machine learning
{x}}))} where H {\displaystyle H} indicates the Heaviside step function. However, this loss function is non-convex and non-smooth, and solving for the
Loss functions for classification
Loss_functions_for_classification
Mathematical function of two variables; outputs 1 if they are equal, 0 otherwise
comb. Dirac measure Heaviside step function Indicator function Levi-Civita symbol Minkowski metric 't Hooft symbol Unit function XNOR gate Nakahara, Mikio
Kronecker_delta
present if they are close according to a function of the metric (typically either a Heaviside step function resulting in deterministic connections between
Hyperbolic_geometric_graph
Algorithm for supervised learning of binary classifiers
networks, a perceptron is an artificial neuron using the Heaviside step function as the activation function. The perceptron algorithm is also termed the single-layer
Perceptron
belongs to some subset. Step function: A finite linear combination of indicator functions of half-open intervals. Heaviside step function: 0 for negative arguments
List of mathematical functions
List_of_mathematical_functions
Uniform distribution on an interval
continuous uniform distribution may also be expressed in terms of the Heaviside step function as: f ( x ) = H ( x − a ) − H ( x − b ) b − a , {\displaystyle
Continuous uniform distribution
Continuous_uniform_distribution
Type of mathematical function
piecewise constant function Boxcar function, Heaviside step function Sign function Triangular function An approximation to a known curve can be found
Piecewise_linear_function
Method for assigning values to integrals
appears, for example, in the Fourier transform of the sign function and the Heaviside step function. To prove the existence of the limit lim ε → 0 + ∫ ε +
Cauchy_principal_value
Topics referred to by the same term
numbers H, the Heaviside step function h, impulse response in LTI system theory H, system function, system response, or transfer function in LTI system
H_(disambiguation)
Mathematical function
some points. For example The Heaviside step function is defined everywhere, but not continuous at zero. Some functions are defined and continuous everywhere
Function_of_a_real_variable
Characteristic time in a system
response, or system output. Classical examples for f(t) are: The Heaviside step function, often denoted by u(t): u ( t ) = { 0 , t < 0 1 , t ≥ 0 {\displaystyle
Time_constant
Function in quantum field theory showing probability amplitudes of moving particles
denotes the Hamiltonian, δ(x) denotes the Dirac delta-function and Θ(t) is the Heaviside step function. The kernel of the above Schrödinger differential operator
Propagator
[|X-t||\tau -H(t-X)|],\end{aligned}}} where H {\displaystyle H} is the Heaviside step function; analogously, expectile regression minimizes an asymmetric L 2
Expectile
Mathematical function with no sudden changes
that the sinc function is continuous function on all real numbers. An example of a discontinuous function is the Heaviside step function H {\displaystyle
Continuous_function
Quick, temporary change in amplitude of electrical signals
shape of the Dirac delta function. It has the properties of infinite amplitude and its integral is the Heaviside step function. Equivalently, it has zero
Pulse_(signal_processing)
Electrical resonant circuit
input voltage. Two common cases are the Heaviside step function and a sine wave. For a Heaviside step function we get v i n ( t ) = M u ( t ) , {\displaystyle
LC_circuit
Linear transform from the time domain to the frequency domain
{\displaystyle x[n]=(0.5)^{n}\,u[n]} (where u {\displaystyle u} is the Heaviside step function). Expanding x [ n ] {\displaystyle x[n]} on the interval ( − ∞
Z-transform
Mathematical operation
transform, and the theory of the gamma function and allied special functions. The Mellin transform of a complex-valued function f defined on R + × = ( 0 , ∞ )
Mellin_transform
Fifth letter of the Greek alphabet
{\displaystyle \varepsilon \neq 0} . it is sometimes used to denote the Heaviside step function. in set theory, the epsilon numbers are ordinal numbers that satisfy
Epsilon
Measure for evaluating probabilistic forecasts
_{\mathbb {R} }(F(x)-H(x-y))^{2}dx} where H {\displaystyle H} is the Heaviside step function and y ∈ R {\displaystyle y\in \mathbb {R} } is the observation
Scoring_rule
Gradient descent learning rule in machine learning
derivation is different. The perceptron uses the Heaviside step function as the activation function g ( h ) {\displaystyle g(h)} , and that means that
Delta_rule
This is a list of some well-known periodic functions. The constant function f (x) = c, where c is independent of x, is periodic with any period, but lacks
List_of_periodic_functions
Inputs for which a function's value is non-zero
a distribution fails to be a smooth function. For example, the Fourier transform of the Heaviside step function can, up to constant factors, be considered
Support_(mathematics)
Function of propagation delay and Doppler frequency
A(u(t)-u(t-\tau ))\,} where u ( t ) {\displaystyle u(t)} is the Heaviside step function. The matched filter output is given by the autocorrelation of the
Ambiguity_function
Electric circuit composed of resistors and capacitors
{t}{RC}}}u(t)={\frac {1}{\tau }}e^{-{\frac {t}{\tau }}}u(t)\,,} where u(t) is the Heaviside step function and τ = RC is the time constant. Similarly, the impulse response
RC_circuit
Limit of sequence of smooth functions
the indicator is also analogous to the second derivative of the Heaviside step function in one dimension. The Laplacian of the indicator can be thought
Laplacian_of_the_indicator
Special function defined by an integral
integral is considered as the convolution of the sinc function with the Heaviside step function, this corresponds to truncating the Fourier series, which
Trigonometric_integral
Dirichlet function, the sign function and the Heaviside step function (except possibly at 0). Integer-valued functions defined on the domain of non-negative
Integer-valued_function
Family of interpolation and clamping functions
return x; } Our original smoothstep function can be rewritten as follows, in terms of the Heaviside step function: S 1 ( x ) = H ( x ) ( 3 x 2 − 2 x 3
Smoothstep
Framework for machine learning
y)=\theta (-yf(\mathbf {x} ))} where θ {\displaystyle \theta } is the Heaviside step function. In machine learning problems, a major problem that arises is that
Statistical_learning_theory
Summatory function of the Möbius function
_{0}^{x}{\frac {y(u)}{u^{2}}}\,du=x^{-1}H(\log x),} where H(x) is the Heaviside step function, B are Bernoulli numbers, and all derivatives with respect to t
Mertens_function
Formula for the sum of an arithmetic function
test function f ( 1 / x ) = θ ( x − 1 ) , {\displaystyle f(1/x)=\theta (x-1),} for θ ( x ) {\displaystyle \theta (x)} the Heaviside step function. Perron
Perron's_formula
Topics referred to by the same term
\theta _{\alpha }(\beta )} Heaviside step function, sometimes denoted θ ( x ) {\displaystyle \theta (x)} Lovász theta function, an upper bound on the Shannon
Theta function (disambiguation)
Theta_function_(disambiguation)
Mathematical model in economics
{t}+f_{t+1}\left(I+x_{t}-d_{t}\right)\right]} Where H() is the Heaviside step function. Wagner and Whitin proved the following four theorems: There exists
Dynamic_lot-size_model
Topics referred to by the same term
crater) Heaviside condition Heaviside cover-up method Heaviside layer or Kennelly–Heaviside layer Heaviside step function Heaviside's dolphin, named in honour
Heaviside_(disambiguation)
Better to receive money now than later
b(t;u):=H(u-t)\cdot \exp \left(-\int _{t}^{u}r(v)\,dv\right)} where H is the Heaviside step function. The notation " ; u {\displaystyle ;u} " is to emphasize that u
Time_value_of_money
Mathematical notation
{\displaystyle \mathbf {I} _{A}(x)=[x\in A].} The Heaviside step function, sign function, and absolute value function are also easily expressed in this notation:
Iverson_bracket
important than precision. The most extreme examples are the sign function or Heaviside step function, which go from −1 to 1 or 0 to 1 (which to use depends on
Hard_sigmoid
{\displaystyle F(x)=2H(x-1)-1} and H ( x ) {\displaystyle H(x)} is the Heaviside step function If x {\displaystyle x} is expressed in radians: lim x → a sin
List_of_limits
Mathematical operation
simply a form of Fourier analysis, though more general. If u is the Heaviside step function, equal to zero when its argument is less than zero, to one-half
Two-sided_Laplace_transform
Measure of positive and negative charges
surface, but is zero outside. That is, the dipole density includes a Heaviside step function locating the dipoles inside the surface. A brute force evaluation
Electric_dipole_moment
Second-order differential operator
\left(t-{\frac {r}{c}}\right)} where Θ {\displaystyle \Theta } is the Heaviside step function. Four-gradient d'Alembert's formula Klein–Gordon equation Relativistic
D'Alembert_operator
Objects that generalize functions
derivative of the distribution corresponding to the Heaviside step function H: For any test function φ {\displaystyle \varphi } , ⟨ H ′ , φ ⟩ = − ∫ − ∞
Distribution (mathematical analysis)
Distribution_(mathematical_analysis)
Signal processing conducted on analog signals
frequencies are represented in the input A unit step function, also called the Heaviside step function, is a signal that has a magnitude of zero before
Analog_signal_processing
Pair of polynomial sequences
two sequences of orthogonal polynomials related to the cosine and sine functions, notated as T n ( x ) {\displaystyle T_{n}(x)} and U n ( x ) {\displaystyle
Chebyshev_polynomials
outside of it. It can be presented as a difference between two Heaviside step functions of amplitude 1. It is used in crystallography to account for irregularities
Crenel_function
French mathematician (1915–2002)
distributions clarified the (then) mysteries of the Dirac delta function and Heaviside step function. It helps to extend the theory of Fourier transforms and
Laurent_Schwartz
Generalization of the hypergeometric function
H denotes the Heaviside step function. The subsequent list shows how some higher functions can be expressed in terms of the G-function: γ ( α , x ) =
Meijer_G-function
Topics referred to by the same term
Hartsville Regional Airport's IATA code Haversine, a trigonometric function Heaviside step function Helenium virus S High vaginal swab High Voltage Software Hilversum
HVS
Symbols for constants, special functions
in mathematical finance in set theory, a certain ordinal number Heaviside step function θ {\displaystyle \theta } (lowercase) represents: a plane angle
Greek letters used in mathematics, science, and engineering
Greek_letters_used_in_mathematics,_science,_and_engineering
Technique to solve differential equations
mathematical than physical, the unit function more physical than mathematical. The operator p in the Heaviside calculus initially is to represent the
Operational_calculus
{e^{-y^{2}/2}}{\sqrt {2\pi }}}\right)} where H(x) is the Heaviside step function and δ(x) is the Dirac delta function. The third moments are easily calculated by integrating
Coskewness
condition for Hölder continuity Dirac delta function Heaviside step function Hilbert transform Green's function Bounded variation Total variation Second
List_of_real_analysis_topics
Type of generalized function
a hyperfunction, represented by either (f, 0) or (0, −f). The Heaviside step function can be represented as H ( x ) = ( 1 − 1 2 π i log ( z ) , − 1
Hyperfunction
Integral approximation method popular in condensed matter physics
Here k B T = β − 1 {\displaystyle k_{\rm {B}}T=\beta ^{-1}} and Heaviside step function − θ ( − ϵ ) {\displaystyle -\theta (-\epsilon )} subtracts the
Sommerfeld_expansion
1943 paper proposing artificial neural networks
_{i}(t)\right),} where H {\displaystyle H} is the Heaviside step function (outputting 1 if the input is greater than or equal to 0, and 0
A Logical Calculus of the Ideas Immanent in Nervous Activity
A_Logical_Calculus_of_the_Ideas_Immanent_in_Nervous_Activity
1 minus the cosine of an angle
processing and filtering is also sometimes used for the unrelated Heaviside step function. The Āryabhaṭīya by Āryabhaṭa Haslett, Charles (September 1855)
Versine
Probability distribution
dx\end{aligned}}} where u ( ⋅ ) {\displaystyle u(\cdot )} is the Heaviside step function and serves to limit the region of integration to values of x {\displaystyle
Distribution of the product of two random variables
Distribution_of_the_product_of_two_random_variables
Procedure of ordering a product operators
_{y}-\tau _{x})B(y)A(x),} where θ {\displaystyle \theta } denotes the Heaviside step function and the ± {\displaystyle \pm } depends on if the operators are
Path-ordering
Equation involving both integrals and derivatives of a function
\qquad x\geq 0\\0,\qquad x<0\end{array}}\right.} is the Heaviside step function. The Laplace transform is defined by, U ( s ) = L { u ( x ) } =
Integro-differential_equation
Control concept
initial effect Stability criterion Step response – Time behavior of a system controlled by Heaviside step functions W. Ross Ashby (1957). "Chapter 12:
Negative_feedback
Integral transform used in various branches of mathematics
{dy}{\sqrt {y^{2}-r^{2}}}}.} where δ is the Dirac delta function and H(x) the Heaviside step function. The extended version of the Abel transform for discontinuous
Abel_transform
\mu (n)} , which generally denotes the Möbius function). Möbius inversion formula Heaviside step function Kronecker delta Estrada, Ricardo (1995), "Dirichlet
Unit_function
Probability distribution in measure theory
For example, the Dirac delta function is a singular measure. Example. A discrete measure. The Heaviside step function on the real line, H ( x ) = d
Singular_measure
Neuromorphic data-processing model
threshold parameter. Equation 3 can be written by using the Heaviside step function. The weight functions w ~ ( x → ) {\displaystyle {\widetilde {w}}({\vec {x}})}
Receptron
Euclidean norm) and Θ ( ⋅ ) {\displaystyle \Theta (\cdot )} the Heaviside step function. If only a time series is available, the phase space can be reconstructed
Correlation_integral
Dimensionless number characterising the behavior of particles suspended in a fluid flow
possible when the forcing function v f ( t ) = V u − Δ V H ( t ) {\displaystyle v_{f}(t)=V_{u}-\Delta VH(t)} is a Heaviside step function; representing particles
Stokes_number
Quantum theory of interacting electron gas
f_{\mathbf {k} }(T=0)=\Theta (k_{\mathrm {F} }-|\mathbf {k} |)} is a Heaviside step function, where k F {\displaystyle k_{\mathbf {F} }} is the Fermi wave vector
Lindhard_theory
Function in q-analog theory
{\displaystyle r=\exp(4\pi ^{2}/\log q)} , H {\displaystyle H} denotes the Heaviside step function, B k {\displaystyle B_{k}} stands for the Bernoulli number, L i
Q-gamma_function
HEAVISIDE STEP-FUNCTION
HEAVISIDE STEP-FUNCTION
Boy/Male
Australian, Danish, Finnish, French, German, Swedish, Teutonic
Stone
Girl/Female
Hindu, Indian
Grading; Step by Step Achiever
Male
English
Short form of English Stephen, STE means "crown."
Boy/Male
Anglo, British, Christian, English
House Guard
Male
English
Variant spelling of English unisex Steph, STEF means "crown."
Boy/Male
Anglo Saxon
Stem.
Boy/Male
English
Austere
Boy/Male
British, English
A Son of Athena
Male
English
Unisex short form of English Stephen and Stephanie, both STEPH means "crown."
Girl/Female
Greek
One who turns.
Boy/Male
Hebrew
Stop.
Boy/Male
Gujarati, Hindu, Indian, Kannada
Growing Step by Step; Prosperity
Male
English
Short form of English Stewart, STEW means "steward."
Boy/Male
Indian, Sikh
First Step
Boy/Male
Hebrew Biblical
Stop.
Girl/Female
Indian
Step Forward
Boy/Male
British, English, Jamaican
Shepherd
Male
Swedish
Swedish form of Old Norse Steinn, STEN means "stone."
Boy/Male
Scottish
Steward.
Girl/Female
Arabic, Gujarati, Hindu, Indian, Kannada, Muslim
The First Step
HEAVISIDE STEP-FUNCTION
HEAVISIDE STEP-FUNCTION
Boy/Male
Norse
Famous son.
Boy/Male
Indian
The resurrector
Male
Hebrew
Variant spelling of Hebrew Zeeb, ZEV means "wolf."Â
Male
English
Anglicized form of Hebrew Eliysha, ELISHA means "God is salvation." In the bible, this is the name of the prophet who succeeded Elijah.
Boy/Male
Anglo, British, English, Finnish, French, Swedish
Lives in the Valley; Valley; Usually with a Stream; Strong; Healthy
Boy/Male
Arabic
Victory; Help
Girl/Female
Afghan, Arabic, Australian, Muslim
Safety; Security; Peace
Girl/Female
Muslim
Of light. Luminous.
Girl/Female
Norse
A giant.
Girl/Female
Arabic, British, Islamic, Malaysian, Muslim, Pakistani, Urdu
Good
HEAVISIDE STEP-FUNCTION
HEAVISIDE STEP-FUNCTION
HEAVISIDE STEP-FUNCTION
HEAVISIDE STEP-FUNCTION
HEAVISIDE STEP-FUNCTION
v. t.
To obstruct; to render impassable; as, to stop a way, road, or passage.
a.
Permitting one to stop over; as, a stop-over check or ticket. See To stop over, under Stop, v. i.
n.
See Stee.
v. t.
To mount by steps; to go through with step by step.
v. t.
To remove the stem or stems from; as, to stem cherries; to remove the stem and its appendages (ribs and veins) from; as, to stem tobacco leaves.
v. i.
To cease to go on; to halt, or stand still; to come to a stop.
v. i.
The space passed over by one movement of the foot in walking or running; as, one step is generally about three feet, but may be more or less. Used also figuratively of any kind of progress; as, he improved step by step, or by steps.
v. i.
A small space or distance; as, it is but a step.
a.
To walk; to go on foot; esp., to walk a little distance; as, to step to one of the neighbors.
n.
A stem-winding watch.
v. t.
To arrest the progress of; to hinder; to impede; to shut in; as, to stop a traveler; to stop the course of a stream, or a flow of blood.
v. t.
To fix the foot of (a mast) in its step; to erect.
a.
Wound by mechanism connected with the stem; as, a stem-winding watch.
v. i.
One of a series of offsets, or parts, resembling the steps of stairs, as one of the series of parts of a cone pulley on which the belt runs.
v. t.
Excessive; as, a steep price.
v. t.
Making a large angle with the plane of the horizon; ascending or descending rapidly with respect to a horizontal line or a level; precipitous; as, a steep hill or mountain; a steep roof; a steep ascent; a steep declivity; a steep barometric gradient.
v. i.
Gait; manner of walking; as, the approach of a man is often known by his step.
v. t.
To oppose or cut with, or as with, the stem of a vessel; to resist, or make progress against; to stop or check the flow of, as a current.
n.
Anything resembling a stem or stalk; as, the stem of a tobacco pipe; the stem of a watch case, or that part to which the ring, by which it is suspended, is attached.
v. t.
To boil slowly, or with the simmering or moderate heat; to seethe; to cook in a little liquid, over a gentle fire, without boiling; as, to stew meat; to stew oysters; to stew apples.