1D signal Fourier and Inverse Fourier transform filter.

package.json

@@ -36,8 +36,10 @@
     "file-saver": "^1.3.3",
     "geotiff": "^0.4.1",
     "js-md5": "^0.4.2",
+    "ndarray": "^1.0.18",
+    "ndarray-fft": "^1.0.3",
     "pako": "^1.0.4",
-    "qeegmodfileparser": "github:jonathanlurie/qeegmodfileparser",
+    "qeegmodfile": "github:jonathanlurie/qeegmodfile",
     "rollup-plugin-bundle-worker": "^0.1.0"
   },
   "devDependencies": {

src/core/Filter.js

@@ -45,7 +45,7 @@ class Filter extends PixpipeObject {
     this._timer = {};
 
     this._isOutputReady = false;
-    
+
     this.setMetadata("time", true);
 
   }
@@ -247,15 +247,15 @@ class Filter extends PixpipeObject {
     var that = this;
     var inputCategories = Object.keys( this._inputValidator );
     var valid = true;
-    
+
     if(inputCategories.length == 0){
       valid = false;
       console.warn("No input validator was added. Filter cannot run. Use addInputValidator(...) to specify input types.");
     }
 
     inputCategories.forEach( function(key){
       var inputOfCategory = that._getInput( key );
-      
+
       if(inputOfCategory){
         if("isOfType" in inputOfCategory){
           valid = valid && inputOfCategory.isOfType( that._inputValidator[ key ] )
@@ -266,13 +266,13 @@ class Filter extends PixpipeObject {
             valid = false;
           }
         }
-          
+
       }
       // input simply not existing!
       else{
         valid = false;
       }
-    
+
     });
 
     if(!valid){
@@ -316,7 +316,7 @@ class Filter extends PixpipeObject {
   * @param {String} recordName - name of the record
   */
   addTimeRecord( recordName ){
-    this._timer[ recordName ] = performance.now();
+    this._timer[ recordName ] = 0;
   }
 
 
@@ -356,24 +356,24 @@ class Filter extends PixpipeObject {
   */
   triggerEvent( eventName /* any other arguments to follow */ ){
     var returnValue = null;
-    
+
     if(this.hasEvent(eventName)){
       if( arguments.length > 1 ){
-        
+
         // a-la-mano slicing argument array to comply with V8 JS engine optimization...
         var argToSend = [];
         for(var i=1; i<arguments.length; i++){
           argToSend.push( arguments[i] );
         }
-        
+
         returnValue = this._events[eventName].apply(this, argToSend )
       }else{
         returnValue = this._events[eventName].call(this);
       }
     }else{
       console.warn("The event " + eventName + " does not exist.");
     }
-    
+
     return returnValue;
   }
 

src/core/Signal1D.js

@@ -0,0 +1,44 @@
+import { PixpipeContainer } from './PixpipeContainer';
+
+class Signal1D extends PixpipeContainer {
+  constructor() {
+    super();
+    this._type = Signal1D.TYPE();
+    this.setMetadata('length', 0);
+  }
+
+  static TYPE() {
+    return 'SIGNAL1D';
+  }
+
+  getData() {
+    return this._data;
+  }
+
+  setData(array, deepCopy = false) {
+    if (deepCopy) {
+      this._data = new array.constructor(array);
+    } else {
+      this._data = array;
+    }
+
+    this.setMetadata('length', array.length);
+  }
+
+  clone(){
+    const copy = new Signal1D();
+    if (this._data) {
+      copy.setData(this._data, true);
+    }
+    return copy;
+  }
+
+  hollowClone(){
+    const copy = new Signal1D();
+    const length = this.getMetadata('length');
+    copy.setData( new Float32Array(length).fill(0) );
+    return copy
+  }
+}
+
+export { Signal1D }

src/decoder/EegModDecoder.js

@@ -1,36 +1,36 @@
 import { Filter } from '../core/Filter.js';
-import QeegModFileParser from 'qeegmodfileparser';
+import { QeegModFileParser } from 'qeegmodfile';
 
 
 class EegModDecoder extends Filter {
-  
+
   constructor() {
     super();
     this.addInputValidator(0, ArrayBuffer);
     this.setMetadata("debug", false);
-    
+
     // a soon-to-be DataView to read the input buffer
     this._view = null;
   }
-  
+
   _run(){
     var inputBuffer = this._getInput(0);
 
     if(!inputBuffer){
       console.warn("EegModDecoder requires an ArrayBuffer as input \"0\". Unable to continue.");
       return;
     }
-    
+
     var modParser = new QeegModFileParser();
     modParser.setRawData( inputBuffer );
     var qeegData = modParser.parse();
-    
+
     if( qeegData ){
       this._output[0] = qeegData;
     }
-    
+
   }
-  
+
 } /* END of class EegModDecoder */
 
 export { EegModDecoder }

src/filter/FourierSignalFilters.js

@@ -0,0 +1,52 @@
+import ndarray from 'ndarray';
+import ft from 'ndarray-fft';
+
+import { Filter } from '../core/Filter';
+import { Signal1D } from '../core/Signal1D';
+
+const DIRECTIONS = {
+  'FORWARD': 1,
+  'INVERSE': -1,
+};
+
+class BaseFourierSignalFilter extends Filter {
+  constructor(direction) {
+    super();
+    this.direction = direction;
+    if (DIRECTIONS[this.direction] === undefined) {
+      throw new Error(`${this.direction} is not a valid fourier transform direction. Please try one of: ${Object.keys(DIRECTIONS)}`);
+    }
+    this.addInputValidator(0, Signal1D);
+  }
+  _run() {
+    if( ! this.hasValidInput()){
+      console.warn("A filter of type BaseFourierSignalFilter requires 1 input of Signal1D.");
+      return;
+    }
+    const inputSignal = this._getInput(0);
+    const length = inputSignal.getMetadata('length');
+    const real = ndarray(inputSignal.clone().getData(), [length]);
+    const img = ndarray(inputSignal.hollowClone().getData(), [length]);
+    this.setMetadata('direction', this.direction);
+
+    ft(DIRECTIONS[this.direction], real, img);
+    this._output[0] = new Signal1D();
+    this._output[0].setData(real.data);
+    this._output[1] = new Signal1D();
+    this._output[1].setData(img.data);
+  }
+}
+
+class ForwardFourierSignalFilter extends BaseFourierSignalFilter {
+  constructor() {
+    super('FORWARD');
+  }
+}
+
+class InverseFourerSignalFilter extends BaseFourierSignalFilter {
+  constructor() {
+    super('INVERSE');
+  }
+}
+
+export { ForwardFourierSignalFilter, InverseFourerSignalFilter }

src/pixpipe.js

@@ -5,6 +5,7 @@
 // core classes
 export { PixpipeObject } from './core/PixpipeObject.js';
 export { Filter } from './core/Filter.js';
+export { Signal1D } from './core/Signal1D.js'
 export { Image2D } from './core/Image2D.js';
 export { Image3D } from './core/Image3D.js';
 export { ImageToImageFilter } from './core/ImageToImageFilter.js';
@@ -30,7 +31,8 @@ export { EegModDecoder } from './decoder/EegModDecoder.js';
 export { PixBinEncoder } from './decoder/PixBinEncoder.js';
 export { PixBinDecoder } from './decoder/PixBinDecoder.js';
 
-// filters - processing of Images2D
+// filters - processing of Images2D and Signal1D
+export { ForwardFourierSignalFilter, InverseFourerSignalFilter } from './filter/FourierSignalFilters.js';
 export { ForEachPixelImageFilter } from './filter/ForEachPixelImageFilter.js';
 export { SpectralScaleImageFilter } from './filter/SpectralScaleImageFilter.js';
 export { ImageBlendExpressionFilter } from './filter/ImageBlendExpressionFilter.js';