Sinc
block Sinc "Generate sinc signal"
import Modelica.Constants.pi;
import Modelica.Constants.eps;
parameter Real amplitude = 1 "Amplitude of sine wave"
annotation (Dialog(groupImage = "modelica://Modelica/Resources/Images/Blocks/Sources/Sinc.png"));
parameter SI.Frequency f(start = 1) "Frequency of sine wave";
extends Interfaces.SignalSource;
protected
SI.Angle x = 2 * pi * f * (time - startTime);
equation
y = offset + (if time < startTime then 0 else amplitude * (if noEvent(time - startTime < eps) then 1 else sin(x) / x));
annotation (
Icon(
coordinateSystem(
preserveAspectRatio = true,
extent = {
{-100, -100},
{100, 100}}),
graphics = {
Line(
points = {
{-80, 68},
{-80, -80}},
color = {192, 192, 192}),
Polygon(
points = {
{-80, 90},
{-88, 68},
{-72, 68},
{-80, 90}},
lineColor = {192, 192, 192},
fillColor = {192, 192, 192},
fillPattern = FillPattern.Solid),
Line(
points = {
{-90, 0},
{68, 0}},
color = {192, 192, 192}),
Polygon(
points = {
{90, 0},
{68, 8},
{68, -8},
{90, 0}},
lineColor = {192, 192, 192},
fillColor = {192, 192, 192},
fillPattern = FillPattern.Solid),
Text(
extent = {
{-147, -152},
{153, -112}},
textString = "f=%f",
textColor = {0, 0, 0}),
Line(
points = {
{-80, 80},
{-76, 78.7},
{-72, 74.8},
{-68, 68.7},
{-64, 60.5},
{-60, 50.9},
{-56, 40.4},
{-52, 29.4},
{-48, 18.7},
{-44, 8.7},
{-40, 0},
{-36, -7.2},
{-32, -12.5},
{-28, -15.8},
{-24, -17.3},
{-20, -17},
{-16, -15.1},
{-12, -12.1},
{-8, -8.3},
{-4, -4.1},
{0, 0},
{4, 3.7},
{8, 6.8},
{12, 9},
{16, 10.1},
{20, 10.2},
{24, 9.3},
{28, 7.6},
{32, 5.3},
{36, 2.7},
{40, 0},
{44, -2.5},
{48, -4.7},
{52, -6.2},
{56, -7.1},
{60, -7.3},
{64, -6.7},
{68, -5.6},
{72, -3.9},
{76, -2},
{80, 0}},
smooth = Smooth.Bezier)}),
Documentation(info = "<html>\n<p>\nThe Real output y is a sinc signal: <code> amplitude*(sin(2*π*f*t))/((2*π*f*t))</code>\n</p>\n<p>\n<img src=\"modelica://Modelica/Resources/Images/Blocks/Sources/Sinc.png\"\n alt=\"Sinc.png\">\n</p>\n</html>"));
end Sinc;