library/src/main/java/com/github/clans/fab/FloatingActionButton.java
public void setShadowRadius(int dimenResId) {
        int shadowRadius = getResources().getDimensionPixelSize(dimenResId);
        if (mShadowRadius != shadowRadius) {
            mShadowRadius = shadowRadius;
            requestLayout();
            updateBackground();
        }
    }
public void setShadowRadius(int dimenResId) {
        int shadowRadius = getResources().getDimensionPixelSize(dimenResId);
        if (mShadowRadius != shadowRadius) {
            mShadowRadius = shadowRadius;
            requestLayout();
            updateBackground();
        }
    }
Sets the shadow radius of the <b>FloatingActionButton</b> and invalidates its layout.

@param dimenResId the resource identifier of the dimension