Blank Heatmap on iOS

Hello, I’ve been trying to create a SCIUniformHeatMap, but I only get a blank, black screen.
Can anyone recommend why colors and the graph aren’t showing up? Thanks

var ecmSurface: SCIChartSurface = SCIChartSurface()
var ecmDataSeries = SCIUniformHeatmapDataSeries(xType: .double, yType: .double, zType: .double, xSize: ReviewModeData.MATRIX_COLUMNS, ySize:ReviewModeData.MATRIX_ROWS)
var heatmapRenderableSeries: SCIFastUniformHeatmapRenderableSeries = SCIFastUniformHeatmapRenderableSeries()
private let countColors = 6
private var colorRGBArray: [UIColor] = [
UIColor(red: 0.0/255.0, green: 0.0/255.0, blue: 131.0/255.0, alpha: 1),
UIColor(red: 0.0/255.0, green: 0.0/255.0, blue: 255.0/255.0, alpha: 1),
UIColor(red: 0.0/255.0, green: 255.0/255.0, blue: 255.0/255.0, alpha: 1),
UIColor(red: 255.0/255.0, green: 255.0/255.0, blue: 0.0/255.0, alpha: 1),
UIColor(red: 255.0/255.0, green: 0.0/255.0, blue: 0.0/255.0, alpha: 1),
UIColor(red: 128.0/255.0, green: 0.0/255.0, blue: 0.0/255.0, alpha: 1)
]
for i in 0..<ReviewModeData.MATRIX_COLUMNS {
for j in 0 ..< ReviewModeData.MATRIX_ROWS {
ecmDataSeries.update(z: ecm2DMatrix[i][j], atX: i, y: j)
}
}
var colorZValueArray: [Double] = determineColorMapValues(clim1: 0, clim2: 1);
var colorMap = SCIColorMap(colors: colorRGBArray, andStops: colorZValueArray as [NSNumber])

//configure ECM heatmap
heatmapRenderableSeries.minimum = ReviewModeData.ECM_CLIM1
heatmapRenderableSeries.maximum = ReviewModeData.ECM_CLIM2
heatmapRenderableSeries.dataSeries = ecmDataSeries
heatmapRenderableSeries.colorMap = colorMap!