smart_lorentz_gauss 2.1.2

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Smart Lorentz Gauss #

What the package can do for you #

This package provides functionalities to compute an n-dimensional mixed Lorentz-Gauss line shape, also called an n-dimensional Pseudo-Voigt function. Typically such functions occur in spectroscopic data originating from electro-magnetic radiation. The function can for example be used for fitting or deconvolution of such data, or for simulating (computing) spectra, i.e. as a superposition of several shapes with different parameters.

Example #

The major API functionalities #

  • class LorentzGauss
  1. The following example constructs a LorentzGauss shape with the given amplitude, center, width, and Gaussian fraction.

    LorentzGauss lg = new LorentzGauss.fromPars(amplitude, [center], [width], [0.2]);

  2. The following example computes the value of the above shape value at position x.

    double val = lg.getValueAt(x]);

  3. The following example computes an array of size NPOINTS containing a pure Lorentzian with amplitude 100. The maximum will be at index NPOINTS/4, and line width 20 points at half maximum height.

    Float64List lor = LorentzGauss.array1D(NPOINTS, 100.0, NPOINTS~/4, 20, 0.0, null);

  4. The methods array1D and array2D return an array or a matrix containing a 1D or 2D Lorentz-Gauss function, respectively.

  5. The class Spectrum2D computes a sum of 2D Lorentz-Gauss functions, a '2D spectrum' of such functions.

smart_arrays_base: Basic functions for 1D and 2D arrays

smart_arrays_numerics: Numerics with 1D and 2D arrays

smart_arrays_compress: Compress 1D and 2D arrays to a smaller size.

smart_arrays_sample_data: Computes 1D and 2D arrays containing sample data.

smart_arrays_dbstore: Store 1D and 2D arrays along with metadata on the local device.

smart_arrays_plot_polyline: Plot 1D arrays as polyline along with axes and more.

smart_arrays_peaks: Detect peaks in 1D and 2D arrays.

smart_arrays_contour_finder: Contours the three-dimensional surface represented by the values f(x,y) of a matrix.

smart_arrays_lmfit: Fits (x, y) data given as arrays to a specified model function using the Levenberg-Marquardt algorithm.

smart_signal_processing: Fourier transform and more.

smart_dialogs: Easy-to-use dialogs in Web applications

Smart Lorentz Gauss #

Version history #

2.0.0 - 2019-03-14 First version available on pub site

2.0.1 - 2019-03-14 Minor doc changes

2.0.2 - 2019-03-14 Minor doc changes

2.0.3 - 2019-03-15 Docu updates

2.0.4 - 2019-03-24 Docu updates

2.0.5 - 2019-04-04 Docu updates

2.0.6 - 2019-05-06 Docu updates

2.0.7 - 2019-08-07 Fixed health suggestions of pub.dev

2.0.8 - 2019-08-21 Docu updates

2.0.9 - 2019-09-01 Result of example is displayed in the browser

2.0.10 - 2019-09-01 Docu updates

2.0.11 - 2019-09-03 Docu updates

2.0.12 - 2019-09-05 Example updated with mixed shaped

2.0.13 - 2019-09-08 Added function array1D

2.0.14 - 2019-09-08 Function array1D now static member of LorentzGauss class

2.1.0 - 2019-09-18 Added method array2D.

2.1.1 - 2019-09-22 Fixed method array2D, add class Spectrum2D

2.1.2 - 2019-09-23 Renamed class Spectrum2D to class LorentzGaussMatrix

example/example.dart

// Copyright (c) 2019, Dr. Bruno Guigas. All rights reserved. Use of this source
// code is governed by a BSD-style license that can be found in the LICENSE file.
import 'dart:typed_data';
import 'dart:html';
import 'dart:convert';

import 'package:smart_lorentz_gauss/smart_lorentz_gauss.dart';
import 'package:smart_arrays_plot_polyline/smart_arrays_plot_polyline.dart';

/// Creates three arrays containing a Lorentzian, a Gaussian and a mixed
/// line shape. The resulting curves are displayed in the browser.
main() {
  final int NPOINTS = 200; // array length
  List<double> height = [100, 100, 100], // function value of line shape maxima
      center = [120, 120, 120], // the maxima should be at this array position
      width = [15, 15, 15]; // width at half height of maximum (points)
  Float64List lor_array = Float64List(NPOINTS), // array for the Lorentzian
      gaus_array = Float64List(NPOINTS), // array for the Gaussian
      mixed_array = Float64List(NPOINTS); // array for the mixed shape

  // construct 3 line shapes, 100% Lorentzian, 100% Gaussian, mixed 50% / 50%
  LorentzGauss lor =
          LorentzGauss.fromPars(height[0], [center[0]], [width[0]], [0.0]),
      gaus = LorentzGauss.fromPars(height[1], [center[1]], [width[1]], [1.0]),
      mixed = LorentzGauss.fromPars(height[1], [center[1]], [width[1]], [0.5]);

  // fill arrays with line shape values
  for (int k = 0; k < NPOINTS; k++) {
    lor_array[k] = lor.getValueAt([k.toDouble()]);
    gaus_array[k] = gaus.getValueAt([k.toDouble()]);
    mixed_array[k] = mixed.getValueAt([k.toDouble()]);
  }

  plotResult(
      [lor_array, gaus_array, mixed_array]); // show computed arrays in browser
}

/// Displays the [arrays] computed by [main] in the browser using the
/// package 'smart_arrays_plot_polyline'.
void plotResult(List<Float64List> arrays) {
  // get divs from 'example.html' (application and plot containers)
  DivElement appDiv = (querySelector("#app_div") as DivElement);
  DivElement plotDiv = (querySelector("#plot_div") as DivElement);

  // the plot will take all available space of [appDiv] in this example
  plotDiv.style
    ..width = "${appDiv.clientWidth}px"
    ..height = "${appDiv.clientHeight}px";

  // setup some polyline, axis and legend attributes
  List<Map<PyA, String>> plotAttr = [
    {PyA.YPOSITION_ZERO: "0.8"}, // rel. y position of the shape value 0
    {PyA.YPOSITION_ZERO: "0.8"},
    {PyA.YPOSITION_ZERO: "0.8"}
  ];

  // x axis labeling
  Map<AxA, String> xaxisAttr = {
    AxA.PHYS_X_START: "0",
    AxA.PHYS_X_WIDTH: "200",
    AxA.LEGENDTEXT: "Number of points"
  };

  // y axis labeling
  Map<AxA, String> yaxisAttr = {AxA.LEGENDTEXT: "Function value"};

  // legend text and position
  Map<LegA, String> legendAttr = {
    LegA.TOP_TITLE: "Lorentz / Gauss line shapes",
    LegA.SUB_TITLES:
        json.encode(["Pure Lorentzian", " Pure Gaussian", " Mixed 50% / 50%"]),
    LegA.X: "45",
    LegA.Y: "15"
  };

  // plot the arrays into [plotDiv]
  SimplePlot(arrays, plotDiv, plotAttr, xaxisAttr, yaxisAttr, legendAttr, null);
}

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:


dependencies:
  smart_lorentz_gauss: ^2.1.2

2. Install it

You can install packages from the command line:

with pub:


$ pub get

with Flutter:


$ flutter pub get

Alternatively, your editor might support pub get or flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:


import 'package:smart_lorentz_gauss/smart_lorentz_gauss.dart';
  
Popularity:
Describes how popular the package is relative to other packages. [more]
22
Health:
Code health derived from static analysis. [more]
100
Maintenance:
Reflects how tidy and up-to-date the package is. [more]
100
Overall:
Weighted score of the above. [more]
61
Learn more about scoring.

We analyzed this package on Dec 5, 2019, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.6.1
  • pana: 0.12.21

Platforms

Detected platforms: Flutter, web, other

No platform restriction found in primary library package:smart_lorentz_gauss/smart_lorentz_gauss.dart.

Dependencies

Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.5.0 <3.0.0
build_runner ^1.6.2 1.7.2
build_web_compilers ^2.1.4 2.7.1
pedantic ^1.7.0 1.9.0
smart_arrays_plot_polyline ^2.0.8 2.2.1
Transitive dependencies
_fe_analyzer_shared 1.0.0
analyzer 0.39.1
archive 2.0.11
args 1.5.2
async 2.4.0
bazel_worker 0.1.23
build 1.2.2
build_config 0.4.1+1
build_daemon 2.1.2
build_modules 2.7.0
build_resolvers 1.3.0
build_runner_core 4.2.0
built_collection 4.3.0
built_value 7.0.0
charcode 1.1.2
checked_yaml 1.0.2
code_builder 3.2.1
collection 1.14.12
convert 2.1.1
crypto 2.1.3
csslib 0.16.1
dart_style 1.3.3
fixnum 0.10.11
front_end 0.1.29
glob 1.2.0
graphs 0.2.0
html 0.14.0+3
http 0.12.0+2
http_multi_server 2.1.0
http_parser 3.1.3
io 0.3.3
js 0.6.1+1
json_annotation 3.0.0
kernel 0.3.29
logging 0.11.3+2
matcher 0.12.6
meta 1.1.8
mime 0.9.6+3
node_interop 1.0.3
node_io 1.0.1+2
package_config 1.1.0
package_resolver 1.0.10
path 1.6.4
pool 1.4.0
protobuf 1.0.1
pub_semver 1.4.2
pubspec_parse 0.1.5
quiver 2.1.2+1
scratch_space 0.0.4+1
shelf 0.7.5
shelf_web_socket 0.2.3
smart_arrays_base 2.1.0
smart_arrays_compress 2.1.0
smart_arrays_contour_finder 2.0.6
smart_arrays_numerics 2.1.1
smart_arrays_sample_data 2.0.5
source_maps 0.10.8
source_span 1.5.5
stack_trace 1.9.3
stream_channel 2.0.0
stream_transform 0.0.20 1.1.0
string_scanner 1.0.5
term_glyph 1.1.0
timing 0.1.1+2
typed_data 1.1.6
watcher 0.9.7+13
web_socket_channel 1.1.0
yaml 2.2.0