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[mathcad] RE: about the function Find

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[mathcad] RE: about the function Find
Author: Boekel, Tiny Van    Posted: Sat, 11 Feb 2006 14:54:50 +0100
Dear Mathcad users I wonder whether someone can help me with the following (small) problem. I am using the function Find for solving an equation in a Solve block using the symbolic equal sign ("the arrow"), see accompanying file (I am using Mathcad 11). I do not seem to be able to capture the solution of the find function into a new parameter, in other words I have to fill in the value manually. There must be a way to do this but I can't figure out how. As you will see it is an iterative calculation; it usually converges after three iterations. there must also be a way to automate this. However, the first mentioned problem is the most annoying one. I hope that someone can help me out here. Thanks a lot in advance! Regards, Tiny van Boekel Wageningen University, NL

[mathcad] RE: about the function Find
Author: Oakley, Philip SELEX UK    Posted: Tue, 14 Feb 2006 14:04:22 +0000
Tiny You are confusing Numeric with Symbolic (a very common problem) Given-Find is a numeric solution construct The symbolic solution construct can also be used but doesn't need variables to have values assigne (they show in red if that is the case) I updated the first equation to be symbolic orientated. I think you should be able to solve for the lot all in one step. Also have a look at http://www.edn.com/article/CA6301377.html for a really good article on pulling together solve and optimisation blocks (you can ignore the electronics elements if it is not your scene) Philip From: Boekel, Tiny van "mailto:Tiny.vanBoekel" Sent: 11 February 2006 13:55 To: Mathcad Discussion List Subject: RE: [mathcad] about the function Find Dear Mathcad users I wonder whether someone can help me with the following (small) problem. I am using the function Find for solving an equation in a Solve block using the symbolic equal sign ("the arrow"), see accompanying file (I am using Mathcad 11). I do not seem to be able to capture the solution of the find function into a new parameter, in other words I have to fill in the value manually. There must be a way to do this but I can't figure out how. As you will see it is an iterative calculation; it usually converges after three iterations. there must also be a way to automate this. However, the first mentioned problem is the most annoying one. I hope that someone can help me out here. Thanks a lot in advance! Regards, Tiny van Boekel Wageningen University, NL ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ********************************************************************
Attachments:  ion pair.mcd

[mathcad] RE: about the function Find
Author: Pergande, Albert N    Posted: Tue, 14 Feb 2006 09:29:17 -0500
You need to "Parameterize the solve block". That is, rather than type "Find() ->" you need to define MyFunc(a):=Find(a) and then call MyFunc. This is described poorly in the quick sheets, but allows a given find block to be a function. In your case, the equation is a simple quadratic, and I assume one root is physically unrealistic. You COULD just write the quadratic eqn and pick the right branch. Once you have the find block as a function, you can put it in a programming loop to iterate. I suspect there are other approaches that will work as well, but this WILL get you to the end. Al Pergande Senior Radar Engineer Lockheed Martin Missiles and Fire Control MP 200 5600 Sandlake Road Orlando, Fl 32819 Voice 407-356-5169 Fax 407-356-0933 "albert.n.pergande" for personal mail - "al" _____ From: Boekel, Tiny van "mailto:Tiny.vanBoekel" Sent: Saturday, February 11, 2006 8:55 AM To: Mathcad Discussion List Subject: RE: [mathcad] about the function Find Dear Mathcad users I wonder whether someone can help me with the following (small) problem. I am using the function Find for solving an equation in a Solve block using the symbolic equal sign ("the arrow"), see accompanying file (I am using Mathcad 11). I do not seem to be able to capture the solution of the find function into a new parameter, in other words I have to fill in the value manually. There must be a way to do this but I can't figure out how. As you will see it is an iterative calculation; it usually converges after three iterations. there must also be a way to automate this. However, the first mentioned problem is the most annoying one. I hope that someone can help me out here. Thanks a lot in advance! Regards, Tiny van Boekel Wageningen University, NL

[mathcad] RE: about the function Find
Author: Boekel, Tiny Van    Posted: Wed, 22 Feb 2006 11:35:17 +0100
Dear Philip Thanks a lot for your help, I appreciate it! Tiny _____ From: Oakley, Philip (SELEX) (UK) "mailto:philip.oakley" Sent: dinsdag 14 februari 2006 15:04 To: Mathcad Discussion List Subject: [mathcad] RE: about the function Find Tiny You are confusing Numeric with Symbolic (a very common problem) Given-Find is a numeric solution construct The symbolic solution construct can also be used but doesn't need variables to have values assigne (they show in red if that is the case) I updated the first equation to be symbolic orientated. I think you should be able to solve for the lot all in one step. Also have a look at http://www.edn.com/article/CA6301377.html for a really good article on pulling together solve and optimisation blocks (you can ignore the electronics elements if it is not your scene) Philip From: Boekel, Tiny van "mailto:Tiny.vanBoekel" Sent: 11 February 2006 13:55 To: Mathcad Discussion List Subject: RE: [mathcad] about the function Find Dear Mathcad users I wonder whether someone can help me with the following (small) problem. I am using the function Find for solving an equation in a Solve block using the symbolic equal sign ("the arrow"), see accompanying file (I am using Mathcad 11). I do not seem to be able to capture the solution of the find function into a new parameter, in other words I have to fill in the value manually. There must be a way to do this but I can't figure out how. As you will see it is an iterative calculation; it usually converges after three iterations. there must also be a way to automate this. However, the first mentioned problem is the most annoying one. I hope that someone can help me out here. Thanks a lot in advance! Regards, Tiny van Boekel Wageningen University, NL ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ********************************************************************

[mathcad] RE: about the function Find
Author: Boekel, Tiny Van    Posted: Wed, 22 Feb 2006 11:39:43 +0100
Dear Al Thanks for your help. I realised the option of the quadratic solution but I was puzzled about the Find function, and was curious about a possible solution. I appreciate your suggestion! Thanks once again, Tiny _____ From: Pergande, Albert N "mailto:albert.n.pergande" Sent: dinsdag 14 februari 2006 15:29 To: Mathcad Discussion List Subject: [mathcad] RE: about the function Find You need to "Parameterize the solve block". That is, rather than type "Find() ->" you need to define MyFunc(a):=Find(a) and then call MyFunc. This is described poorly in the quick sheets, but allows a given find block to be a function. In your case, the equation is a simple quadratic, and I assume one root is physically unrealistic. You COULD just write the quadratic eqn and pick the right branch. Once you have the find block as a function, you can put it in a programming loop to iterate. I suspect there are other approaches that will work as well, but this WILL get you to the end. Al Pergande Senior Radar Engineer Lockheed Martin Missiles and Fire Control MP 200 5600 Sandlake Road Orlando, Fl 32819 Voice 407-356-5169 Fax 407-356-0933 "albert.n.pergande" for personal mail - "al" _____ From: Boekel, Tiny van "mailto:Tiny.vanBoekel" Sent: Saturday, February 11, 2006 8:55 AM To: Mathcad Discussion List Subject: RE: [mathcad] about the function Find Dear Mathcad users I wonder whether someone can help me with the following (small) problem. I am using the function Find for solving an equation in a Solve block using the symbolic equal sign ("the arrow"), see accompanying file (I am using Mathcad 11). I do not seem to be able to capture the solution of the find function into a new parameter, in other words I have to fill in the value manually. There must be a way to do this but I can't figure out how. As you will see it is an iterative calculation; it usually converges after three iterations. there must also be a way to automate this. However, the first mentioned problem is the most annoying one. I hope that someone can help me out here. Thanks a lot in advance! Regards, Tiny van Boekel Wageningen University, NL

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