Dimensionality Reduction as Exercises

digits= ExampleData[{"MachineLearning","MNIST"},
"Data"];sample=RandomSample[digits,2000];
Delete[digits];sample[[1;;7]]
features=DimensionReduce[sample[[All,1]],2,
Method->"TSNE",PerformanceGoal->"Quality"];
bydigits=GroupBy[Thread[features->sample[[All,2]]],
Last->First];
ListPlot[Values[bydigits],PlotLegends->Keys[bydigits],
ImageSize->600,AspectRatio->1,Frame->True]