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Date/Time: Mon, 22 Jan 2018 12:35:22 +0000



Andrews Pitchforks problem - variations in plotted pitchfork as

Support Request:
[2013-04-01 20:51:59]
User99606 - Posts: 9
I'm a regular user of Andrews Pitchforks (as well as Schiff and Modified Schiff Pitchforks) and am having an issue with the forks changing slope significantly when small changes are made to horizontal or vertical scale. Below are a couple of examples of the variations cause by a slight change in the price scale.

Chart 1.jpg shows a Andrews Pitchfork with multiple parallels. Note that the final bar is touching the lower pitchfork parallel. The pitchfork line and final bar intersect at about 14461 on the Y axis.

Chart 2.jpg shows the same chart with a slight change made to the price scale by clicking on the scale and moving the mouse slightly. On this chart the bottom parallel has shifted by around 40 points in relation to the last bar. The low of the last bar remains at 14461, but the parallel has moved down to about 14421.

When there are more bars between the pitchfork's origin points and the bar of interest the variations become even greater making the pitchforks of little use in many instances. In addition, the same kinds of pitchfork slope variations occur when changing the bar spacing and sometimes when simply scrolling right or left on the chart. Please let me know if you'd like me to provide screen captures of these instances.

Is there any way this can be fixed or the severity of the variation in slope reduced?








Date Time Of Last Edit: 2013-04-01 21:23:53
imageChart 1.jpg / V - Attached On 2013-04-01 21:21:55 UTC - Size: 295.84 KB - 156 views
imagechart 2.jpg / V - Attached On 2013-04-01 21:22:13 UTC - Size: 295.45 KB - 167 views
[2013-04-01 21:10:25]
Sierra Chart Engineering - Posts: 56350
We do not see any attachments.
Sierra Chart Support - Engineering Level

Your definitive source for support. Other responses are from users. If possible please keep your questions brief and to the point. Please be aware of support policy:
https://www.sierrachart.com/index.php?l=PostingInformation.php#GeneralInformation

If your question/request has been answered and you do not have anything further, then it is easiest for us if you do not reply again to say thank you.
[2013-04-01 22:26:57]
User99606 - Posts: 9
We do not see any attachments.


I inadvertently hit "Submit" before finishing the message.
Date Time Of Last Edit: 2013-04-01 22:27:12
[2013-04-02 14:06:57]
Al SC Developer - Posts: 434
This is a difficult problem, and has to do with the geometry of the object and the available pixels on the screen. This drawing is made worse due to the number of points per pixel for the symbol you are using, and the very short number of bars in the A-B-C region. The drawing anchors (pitchfork A-B-C points) are used to create the lines. Notice how when you scale, those three points are always correct.

We do have a mechanism that allows you to work around the issue. Instead of using the A-B-C anchors, we have the concept of a secondary anchor. When you adjust the secondary anchor, the B-C-Secondary are fixed and set the lines. The con of this method is that the A point can be off, but it is necessary in order to have the lines plotted in a parallel fashion.

In order to use the secondary anchors, be sure the "Adjust Secondary" command is on your chart drawing menu, by going to Global Settings >> Customize Chart Drawing Menu.

Once enabled, right click the pitchfork drawing near the point where you want to set the secondary anchor, and use the Adjust Secondary menu option. Place and click the mouse where you want to fix the secondary anchor (i.e. a bar high/low). From this point forward, the B-C-secondary points should be maintained. If later you modify the A anchor, the secondary will be reset.
[2013-04-05 21:51:54]
Sierra Chart Engineering - Posts: 56350
Documentation has been updated to explain this:
http://www.sierrachart.com/index.php?l=doc/doc_Tools.html#Pitchfork
Sierra Chart Support - Engineering Level

Your definitive source for support. Other responses are from users. If possible please keep your questions brief and to the point. Please be aware of support policy:
https://www.sierrachart.com/index.php?l=PostingInformation.php#GeneralInformation

If your question/request has been answered and you do not have anything further, then it is easiest for us if you do not reply again to say thank you.

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