FFTDrawer/app/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:mynamespace="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical"
    tools:activity=".MainActivity">
    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <com.feemers.android.fftdrawer.BarChartView
        android:id="@+id/graficView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        mynamespace:backgroundColor="#4C614C"/>
    <TextView
        android:id="@+id/textView2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <com.feemers.android.fftdrawer.BarChartView
        android:id="@+id/graficView2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        mynamespace:backgroundColor="#75455E"/>
</LinearLayout>