How to use the d3-shape.curveMonotoneX function in d3-shape

curveCatmullRomFactory = d3Shape.curveCatmullRomOpen.alpha(0.5);

curveGenerator = d3Shape.curveCatmullRomOpen.alpha(0.5)(context!);  // force context to be non-null with post-fix for mock
curveGenerator = d3Shape.curveCatmullRomOpen.alpha(0.5)(path());

curveCatmullRomFactory = d3Shape.curveCatmullRomClosed;
curveCatmullRomFactory = d3Shape.curveCatmullRomClosed.alpha(0.5);

curveGenerator = d3Shape.curveCatmullRomClosed.alpha(0.5)(context!);  // force context to be non-null with post-fix for mock
curveGenerator = d3Shape.curveCatmullRomClosed.alpha(0.5)(path());

curveFactory = d3Shape.curveLinear;

curveFactory = d3Shape.curveLinearClosed;

curveFactory = d3Shape.curveMonotoneX;

curveFactory = d3Shape.curveMonotoneY;

curveFactory = d3Shape.curveNatural;

curveFactory = d3Shape.curveStep;

curveFactory = d3Shape.curveStepAfter;

curveFactory = d3Shape.curveStepBefore;

// -----------------------------------------------------------------------------------
// Test Link/LinkRadial Generators
// -----------------------------------------------------------------------------------

// Preparatory steps =================================================================

xScaleMax: any;
  yScaleMin: number;
  yScaleMax: number;
  showDataLabel = false;

  curves = {
    Basis: shape.curveBasis,
    'Basis Closed': shape.curveBasisClosed,
    Bundle: shape.curveBundle.beta(1),
    Cardinal: shape.curveCardinal,
    'Cardinal Closed': shape.curveCardinalClosed,
    'Catmull Rom': shape.curveCatmullRom,
    'Catmull Rom Closed': shape.curveCatmullRomClosed,
    Linear: shape.curveLinear,
    'Linear Closed': shape.curveLinearClosed,
    'Monotone X': shape.curveMonotoneX,
    'Monotone Y': shape.curveMonotoneY,
    Natural: shape.curveNatural,
    Step: shape.curveStep,
    'Step After': shape.curveStepAfter,
    'Step Before': shape.curveStepBefore,
    default: shape.curveLinear
  };

  // line interpolation
  curveType: string = 'Linear';
  curve: any = this.curves[this.curveType];
  interpolationTypes = [
    'Basis', 'Bundle', 'Cardinal', 'Catmull Rom', 'Linear', 'Monotone X',
    'Monotone Y', 'Natural', 'Step', 'Step After', 'Step Before'
  ];

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var fp_1 = require("lodash/fp");
var d3_shape_1 = require("d3-shape");
var styles = require("./styles");
var interpolator = {
    cardinal: d3_shape_1.curveCardinal,
    linear: d3_shape_1.curveLinear,
    monotoneX: d3_shape_1.curveMonotoneX,
    monotoneY: d3_shape_1.curveMonotoneY,
    step: d3_shape_1.curveStep,
    stepAfter: d3_shape_1.curveStepAfter,
    stepBefore: d3_shape_1.curveStepBefore,
};
var defaultAccessors = {
    color: function (series, d) { return series.legendColor(); },
    interpolate: function (series, d) { return "linear"; },
    closeGaps: function (series, d) { return true; },
};
var hasValue = function (d) {
    return !!d || d === 0;
};
var aOrB = function (a, b) {
    return hasValue(a) ? a : b;
};

showSeriesOnHover: true,
  curve: shape.curveLinear,
  curveClosed: shape.curveCardinalClosed
};

const  curves = {
  'Basis': shape.curveBasis,
  'Basis Closed': shape.curveBasisClosed,
  'Bundle': shape.curveBundle.beta(1),
  'Cardinal': shape.curveCardinal,
  'Cardinal Closed': shape.curveCardinalClosed,
  'Catmull Rom': shape.curveCatmullRom,
  'Catmull Rom Closed': shape.curveCatmullRomClosed,
  'Linear': shape.curveLinear,
  'Linear Closed': shape.curveLinearClosed,
  'Monotone X': shape.curveMonotoneX,
  'Monotone Y': shape.curveMonotoneY,
  'Natural': shape.curveNatural,
  'Step': shape.curveStep,
  'Step After': shape.curveStepAfter,
  'Step Before': shape.curveStepBefore,
  'default': shape.curveLinear
};


@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['../../node_modules/@swimlane/ngx-ui/release/index.css', './app.component.scss'],
  encapsulation: ViewEncapsulation.None
})
export class AppComponent implements OnInit {