Getting rid of annoying zeroes in algebraic expressions
- To: mathgroup at smc.vnet.net
- Subject: [mg15228] Getting rid of annoying zeroes in algebraic expressions
- From: "Ross, Sean" <rosss at plk.af.mil>
- Date: Wed, 23 Dec 1998 01:04:05 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Let xx be the result of some algebraic manipulations which, for some reason, mathematica thinks the real zeroes ought to be kept and I think they ought to be dropped. xx=0. + (a*f)/(0. + f) + (b*f)/(0. + f) + (c*f)/(0. + f) xx/.Plus[0.,q_]->q returns 0. + (a*f)/(0. + f) + (b*f)/(0. + f) + (c*f)/(0. + f) while 0. + (a*f)/(0. + f) + (b*f)/(0. + f) + (c*f)/(0. + f)/.Plus[0.,q_->q] returns the expected a+b+c. xx is supposed to be equivalent to the expression, but in this case, it is not. I can't write a function to automatically drop zeroes if expressions behave differently when they are alone on an input line and when they are set equal to a symbol. Does anyone know how to eliminate this kind of behavior? I am sure it has something to do with some obscure step in the "standard evaluation cycle" and that there is probably a long, convoluted explanation as to why someone would want this behavior, but I don't and I would appreciate it if someone could tell me how to get rid of it or circumvent it. Thanks, Sean Ross Please reply to rosss at plk.af.mil as I no longer subscribe to the mathgroup. ------_=_NextPart_000_01BE2DE8.422DB28A eJ8+IicUAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEIgAcAGAAAAElQTS5NaWNy b3NvZnQgTWFpbC5Ob3RlADEIAQWAAwAOAAAAzgcMABYADQASACUAAgA9AQEggAMADgAAAM4HDAAW AA0AEgAlAAIAPQEBCYABACEAAAAzRkE5RUYwQkMxOTlEMjExOUIxRTAwODA1RkE3ODcxNgAwBwEE gAEAOAAAAEdldHRpbmcgcmlkIG9mIGFubm95aW5nIHplcm9lcyBpbiBhbGdlYnJhaWMgZXhwcmVz c2lvbnMA9RQBDYAEAAIAAAACAAIAAQOQBgBYCQAAMQAAAAIBcQABAAAAFgAAAAG+LehjCUPqLSKZ ZhHSpREAYJcznZQAAAMA3j+vbwAAAwAIgAggBgAAAAAAwAAAAAAAAEYAAAAAUoUAAOMVAAAeAAmA CCAGAAAAAADAAAAAAAAARgAAAABUhQAAAQAAAAQAAAA4LjUACwAKgAggBgAAAAAAwAAAAAAAAEYA AAAABoUAAAAAAAADAAuACCAGAAAAAADAAAAAAAAARgAAAAABhQAAAAAAAAsAAIAIIAYAAAAAAMAA AAAAAABGAAAAAAOFAAAAAAAACwAUgAggBgAAAAAAwAAAAAAAAEYAAAAADoUAAAAAAAADAAKACCAG AAAAAADAAAAAAAAARgAAAAAQhQAAAAAAAAMAFYAIIAYAAAAAAMAAAAAAAABGAAAAABGFAAAAAAAA AwAXgAggBgAAAAAAwAAAAAAAAEYAAAAAGIUAAAAAAAAeACaACCAGAAAAAADAAAAAAAAARgAAAAA2 hQAAAQAAAAEAAAAAAAAAHgAngAggBgAAAAAAwAAAAAAAAEYAAAAAN4UAAAEAAAABAAAAAAAAAB4A KIAIIAYAAAAAAMAAAAAAAABGAAAAADiFAAABAAAAAQAAAAAAAAALADOACyAGAAAAAADAAAAAAAAA RgAAAAAAiAAAAAAAAAsANYALIAYAAAAAAMAAAAAAAABGAAAAAAWIAAAAAAAAAgEJEAEAAACUAwAA kAMAAI4FAABMWkZ1L8ltawMACgByY3BnMTI1FjIA+Atgbg4QMDMz/QH3IAKkBGUIVQeyAoMAUBMD 1AIAY2gKwHNldCwwIAcTAoB9CoF1Y6MAUAsDdWxuAiBlArEEIEwS4CB4eCBisGUgdGgVgAlwcxRg 4QVAb2YgcwNwFYAHQJBnZWJyC3BjIAOBYwUgFGBhdGkCIAQgd+JoDeBoLCACEAXAFoP1CXBhFoBu GKAAwBWhGdHtDeBhFZELgGsEIBWkB0A0IHoEkG8HkQhgZ2jJBUB0bxVia2UFMQBwWGQgSRqEFZJ5 G/tk6QNgcHAJgC4KogqECoABFUA9MC4gKyAowGEqZikvKCBTINA1IHJiIM5jIMofbC8uElAKQHNb IFAscV9wXS0+cQrjH6YJcHT/CHAAgB9qIF8hbyJ/I4wYUX5sFLAfdBHjDAEr9QvDNH4gJ48onymv LjEkmSVRXSclnwYxFaJleB8gY3SDCYAfamErYitjH13WIAQAFnB1HxBvEtAdMMEcZGVxdWl2B0AJ 8J8cQzNFFeEAkBmSYnUFQL8LgBqCBCAaYBLQGKBpOTE7BCAUgHQfVR1QGmBuJz0FQHcFEDPQFsAY sHVudzPAGAEcUmE5IANxGkJs/mweAB7iG4YGkDhJBCAVcO0SoHYewQaQZgSQN6E9of8YUAnwHcQK wBayFJEWQAOg7wORC4AXsAVAbAuAFrEdIf9AvBLRNyIbYTzCFnAGwy3ArCBEG8IAcHlBsmsUgK0H 4GhGgRxhZUKwbQuA9xfgFYI2EWsLgB0wFlE/g5kYAHI/RYAdUGFtNjG/QWE6MRKgNiEWkRqSZxxS nmQccAPwFaAWdG9iBPC9SaJzM9A+ADlTFYAiTHA/HRELETNwN3FEgDxzY3n6YyvAIh0DFaAX4BWS SbJ/BCA4cEvwAaA9oRpwQaFn8xigBaBudgbwOSA2oTOB/w8BTiRKIRxhGFAeABaCQbL6dwhgbEMh AHBPYjYRSJa/OPQdUEsgO3IdFFO0YR8Q/QlwYwcwO+E6MhZkQbIFoP9T0jPQPZAXYBWARrUW8AVA XwUQSEM6MQWxVyByTCBtnz/AN7E6MB9bLEYgVBKg/RrBLFurCwIGUQORCAASUf8feSSgGWEVwgtQ HgAcYQNgCQQQc0ALUGsuYWb+LkdQAyBKIR1QFIBQsxFB/xYATAEFEBVyN/QZ0gnACGAucB9ZM/UT kQBl0B4AcAABAAAAOAAAAEdldHRpbmcgcmlkIG9mIGFubm95aW5nIHplcm9lcyBpbiBhbGdlYnJh aWMgZXhwcmVzc2lvbnMAAwAmAAAAAAADADYAAAAAAAsAAgABAAAAAwD9P+QEAABAADkAkEgAQugt vgEDAPE/CQQAAB4AMUABAAAABgAAAFJPU1NTAAAAAwAaQAAAAAAeADBAAQAAAAYAAABST1NTUwAA AAMAGUAAAAAAAwCAEP////8CAUcAAQAAADMAAABjPVVTO2E9IDtwPU9SR0FOSVpBVElPTjtsPURF LVgxLTk4MTIyMjIwMTgzN1otMjc2MgAAAgH5PwEAAABOAAAAAAAAANynQMjAQhAatLkIACsv4YIB AAAAAAAAAC9PPU9SR0FOSVpBVElPTi9PVT1QUlMvQ049REVMIFJFQ0lQSUVOVFMvQ049Uk9TU1MA AAAeAPg/AQAAAAsAAABSb3NzLCBTZWFuAAAeADhAAQAAAAYAAABST1NTUwAAAAIB+z8BAAAATgAA AAAAAADcp0DIwEIQGrS5CAArL+GCAQAAAAAAAAAvTz1PUkdBTklaQVRJT04vT1U9UFJTL0NOPURF TCBSRUNJUElFTlRTL0NOPVJPU1NTAAAAHgD6PwEAAAALAAAAUm9zcywgU2VhbgAAHgA5QAEAAAAG AAAAUk9TU1MAAABAAAcwDFPtQegtvgFAAAgwirItQugtvgEeAD0AAQAAAAEAAAAAAAAAHgAdDgEA AAA4AAAAR2V0dGluZyByaWQgb2YgYW5ub3lpbmcgemVyb2VzIGluIGFsZ2VicmFpYyBleHByZXNz aW9ucwAeADUQAQAAADoAAAA8Q0Y2ODVGRUZENjNERDIxMTlCMDMwMDgwNUZBNzg3OTYyNDAzNjJA ZGUteDEucGxrLmFmLm1pbD4AAAALACkAAAAAAAsAIwAAAAAAAwAGEI+jphgDAAcQYAMAAAMAEBAA AAAAAwAREAEAAAAeAAgQAQAAAGUAAABMRVRYWEJFVEhFUkVTVUxUT0ZTT01FQUxHRUJSQUlDTUFO SVBVTEFUSU9OU1dISUNILEZPUlNPTUVSRUFTT04sTUFUSEVNQVRJQ0FUSElOS1NUSEVSRUFMWkVS T0VTT1VHSFRUAAAAAAIBfwABAAAAOgAAADxDRjY4NUZFRkQ2M0REMjExOUIwMzAwODA1RkE3ODc5 NjI0MDM2MkBkZS14MS5wbGsuYWYubWlsPgAAAHoh ------_=_NextPart_000_01BE2DE8.422DB28A--
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