Plotting ExampleWe'll take a following example of data:LSE:VOD date,open,high,low,close,volume
2003/06/02,132.5,134.75,131.5,132.25,295589444
2003/06/03,132.25,132.25,129.5,131.5,269082628
2003/06/04,131.5,133.75,129.25,132,280252100
2003/06/05,132,133.5,128.25,129.75,390012272
2003/06/06,129.75,130.75,126.75,128.5,391269978
2003/06/09,128.5,128.5,125.5,126.75,201315222
2003/06/10,126.75,127.5,125.25,126,370469784
2003/06/11,126,126.5,122.25,124,484700224
2003/06/12,124,126.75,123,124.75,364963148
2003/06/13,124.75,125.5,121.75,122.25,262781674
2003/06/16,122.25,124.25,121.5,122.25,261153162
2003/06/17,122.25,124.5,122.25,123,403637390
2003/06/18,122.25,124.0,121.5,122.5,192966146 and set box size = 1, reversal = 3.
We'll take high and low values for each day, taking high's ceiling and low's floor to obtain integer value for plotting. Thus values will be:2003/06/02,135,131
2003/06/03,133,129
2003/06/04,134,129
2003/06/05,134,128
2003/06/06,131,126
2003/06/09,129,125
2003/06/10,128,125
2003/06/11,127,122
2003/06/12,127,123
2003/06/13,126,121
2003/06/16,125,121
2003/06/17,125,122
2003/06/18,124,121 The price axis values will be somewhere between 135 and 120.
Let's take first column direction from first day of data open and close and decide it will be column of 'O's, as 2 June open is greater than close. Then we plot first O opposite 135 and go down plotting 'O's until 131.
For each data pair (high, low) we check two conditions: let's call them 'column extension' which is to be checked first and 'column reversal' if the first condition is false. If both are false, nothing is to be done.
For the second day we check extension condition: is day's low less than bottom of the current column? It is, so we extend column to 129 and there's no need to check the second condition.
For the third day extension is false, we are still at 129, and so we check for reversal: is day's high greater than or equal to bottom of the column plus reversal amount, i.e. 129+3*1=132? It is, so we go on to the next column of 'X's, which starts one box above previous column's bottom, at 130 and goes on up to 134.
For the fourth day extension condition is about day's high rather than low because now we have a column of 'X's: it is false because day's high is still 134. In the meantime, day's low is 128 which is less than 134-3*1=131 so chart reverses again, and we start a column of 'O's with top box one box below 134, at 133 and bottom box at 128.
Next day extension is true, we plot to more 'O's and we are now at 126. The same happens on 9 June, and we are at 125. But on 10 June low is still 125 so we check for reversal, and it is true. We go up three boxes until 128, then on 11 June reverse again until 122, then up and so on until the end of the data.
Finally we get chart like this:135|X
134|XOX
133|XOXO
132|XOXO
131|XOXO
130| OXO
129| O O
128| OX
127| OXOX
126| OXOXO
125| O OXOX
124| OXOXO
123| OXOXO
122| O OXO
121| O O
|