Ext.js chart series and axis - extjs

Question

Suppose I have some data that I want to display on an Ext.js bar chart and I want my data to revolve around a custom value, "1.0" for example, on the y-axis (versus traditionally "0.0").
Meaning, the picture below has negative values represented with inverted bars, I would like values less than "1.0" to show as an inverted bar on the chart.
Is there a setting that I can set to acheive this? If so, would it be in the series and the axis definition? Maybe the chart itself?
The code for the chart displayed is below:
Ext.require('Ext.chart.*');
Ext.require(['Ext.Window', 'Ext.fx.target.Sprite', 'Ext.layout.container.Fit', 'Ext.window.MessageBox']);
Ext.define('CPI', {
extend: 'Ext.data.Model',
fields: [{
name: 'ReportingPeriod',
type: 'string'
}, {
name: 'CPI_P',
type: 'decimal'
}, {
name: 'CPI_C',
type: 'decimal'
}]
});
var store1 = Ext.create('Ext.data.Store', {
model: 'CPI',
data: [{
ReportingPeriod: 'Period1',
CPI_P: '1.9',
CPI_C: '1.2'
}, {
ReportingPeriod: 'Period2',
CPI_P: '1.2',
CPI_C: '1.1'
}, {
ReportingPeriod: 'Period3',
CPI_P: '0.1',
CPI_C: '0.5'
}, {
ReportingPeriod: 'Period4',
CPI_P: '-0.5',
CPI_C: '0.6'
}, {
ReportingPeriod: 'Period5',
CPI_P: '-0.9',
CPI_C: '0.8'
}, {
ReportingPeriod: 'Period6',
CPI_P: '-1.0',
CPI_C: '-0.6'
}, {
ReportingPeriod: 'Period7',
CPI_P: '-1.1',
CPI_C: '-0.7'
}, {
ReportingPeriod: 'Period8',
CPI_P: '-1.5',
CPI_C: '-0.8'
}]
});
var chart = Ext.create('Ext.chart.Chart', {
style: 'background:#fff',
animate: true,
theme: 'Category1',
store: store1,
width: 300,
height: 300,
renderTo: 'chart',
axes: [{
type: 'Numeric',
position: 'left',
fields: ['CPI_P', 'CPI_C'],
title: 'CPI',
grid: true
}, {
type: 'Category',
position: 'bottom',
fields: ['ReportingPeriod'],
title: 'Reporting Period'
}],
series: [{
type: 'column',
axis: 'left',
xField: 'ReportingPeriod',
yField: 'CPI_P',
markerConfig: {
type: 'cross',
size: 3
},
renderer: function(sprite, record, attr, index, store) {
var value = (record.get('CPI_P') >> 2) % 2;
var color = ['rgb(213, 70, 121)',
'rgb(44, 153, 201)'
][value];
return Ext.apply(attr, {
fill: color
});
}
}]
});
chart.show();
UPDATE
If I add a minimum to y-axis I get closer (sort of)
...
axes: [{
type: 'Numeric',
position: 'left',
fields: ['CPI_P', 'CPI_C'],
title: 'CPI',
grid: true,
minimum: 1,
}....
It's the right idea, because the bars now are relevant to the number 1, but I obviously need to keep the bars on the graph.

Answer 1

What has seemed to work is subtracting 1 from my data and adding 1 to the labels.
axes: [{
type: 'Numeric',
position: 'left',
grid: true,
maximum: 1.0, //will render to 2.0
fields: ['PeriodAmount', 'CumulativeAmount'],
label:{
renderer:function(v){
return (v+1).toFixed(2);
}
}
}...]
This is a viable work around for me, but I wouldn't consider this an elegant answer since it isn't very configurable for custom values. For example, changing this to -1 or 2 would require more work than just changing a simple setting.