set pca as default, warn more seriously

app.py

@@ -159,9 +159,9 @@ with gr.Blocks() as demo:
         with gr.Row():
             with gr.Column():
                 image_input = gr.Image(label="Input Image")
-                algorithm = gr.Radio(["PCA", "TSNE", "UMAP"], label="Algorithm")
+                algorithm = gr.Radio(["PCA", "TSNE", "UMAP"], label="Algorithm", value="PCA")
                 run_button = gr.Button("Run")
-                gr.Markdown("⚠️ UMAP is slow, TSNE is ultra-slow, use resample x<-3 ⚠️")
+                gr.Markdown("⚠️ UMAP is slow, TSNE is ULTRA-slow. They won't run on time. ⚠️")
                 resample_pct = gr.Slider(-5, 0, -3, label="Resample (10^x)*100%")
             with gr.Column():
                 output_image = gr.Image(label="Output Image")