EXCEL SPREADSHEET, something to worry about.
?....... Do you fail to EXCEL Calculation Problems ?...... Numerical errors "? ...
Spreadsheets
always sold as versatile tools and utilities to enable the handling of a lot of numbers and formulas with ease of repetitive calculations in an irreproachable manner and seriousness warranty software creator .
Because of this advantage have been using the EXCEL spreadsheet from Microsoft, both the 2003 version as the 2007 version.
Analemma During the development of the publication on the blog article "CHARTING THE analemma " I relied on this program for a series of repetitive calculations (over 576) of spherical geometry in a "mechanized" in order to reduce the manual and mental effort such repetition creates.
The idea was to determine the length and azimuth of the shadow that should generate a vertical rod to set the points to generate the Analemma Solar, as it would appear when projected on a horizontal sundial.
During the drawing of lines to generate the Analemma, I noticed that the figure showed some irregularities, repeatedly checking the results of EXCEL and plot lines with the computer aided design software I had no choice but to appeal to pocket calculator to verify the calculations made at the points where the finding with the idea of \u200b\u200bfinding an error in the tables and data used in the spreadsheet. The results obtained with the manual procedure differed up to four digits (in my case were degrees inclination) with respect to the values \u200b\u200bproduced by the spreadsheet. As much as I tried fails to find the cause of the discrepancy and concludes that it may be due to rounding used by the spreadsheet and trigonometric functions, or make a mistake that EXCEL.
This detail does not concern me more until I had to make a series of engineering calculations to estimate the pressure drop in a proportional valve. Again, the results started to diverge, gave values \u200b\u200bup to four digits apart. On this occasion there was no trigonometric functions and if you will, the formulas were relatively simple. But I discovered that if the EXCEL sheet made by the (different cells) equations results individual cells is consistent with the values \u200b\u200bobtained with the pocket calculator, even more puzzling behavior.
is unforgivable to me this type of "error" can not be present or be allowed in any type of program to boast (nothing economically by the way) be a "tool" of support for carrying out calculations. The errors committed by the spreadsheet can be so significant that could be the cause of the failure of an engineering job without thinking about the havoc that the administration would represent a small or medium business that relies on this software to "streamline" calculations.
This discovery is regrettable and generates a great deal of mistrust on this very widely used.
I have no choice but from now on to check with my financial calculator all mathematical operations that somehow compromise my work activities ... ...
?....... Do you fail to EXCEL Calculation Problems ?...... Numerical errors "? ...
Spreadsheets
always sold as versatile tools and utilities to enable the handling of a lot of numbers and formulas with ease of repetitive calculations in an irreproachable manner and seriousness warranty software creator .
Because of this advantage have been using the EXCEL spreadsheet from Microsoft, both the 2003 version as the 2007 version.
Analemma During the development of the publication on the blog article "CHARTING THE analemma " I relied on this program for a series of repetitive calculations (over 576) of spherical geometry in a "mechanized" in order to reduce the manual and mental effort such repetition creates.
The idea was to determine the length and azimuth of the shadow that should generate a vertical rod to set the points to generate the Analemma Solar, as it would appear when projected on a horizontal sundial.
During the drawing of lines to generate the Analemma, I noticed that the figure showed some irregularities, repeatedly checking the results of EXCEL and plot lines with the computer aided design software I had no choice but to appeal to pocket calculator to verify the calculations made at the points where the finding with the idea of \u200b\u200bfinding an error in the tables and data used in the spreadsheet. The results obtained with the manual procedure differed up to four digits (in my case were degrees inclination) with respect to the values \u200b\u200bproduced by the spreadsheet. As much as I tried fails to find the cause of the discrepancy and concludes that it may be due to rounding used by the spreadsheet and trigonometric functions, or make a mistake that EXCEL.
This detail does not concern me more until I had to make a series of engineering calculations to estimate the pressure drop in a proportional valve. Again, the results started to diverge, gave values \u200b\u200bup to four digits apart. On this occasion there was no trigonometric functions and if you will, the formulas were relatively simple. But I discovered that if the EXCEL sheet made by the (different cells) equations results individual cells is consistent with the values \u200b\u200bobtained with the pocket calculator, even more puzzling behavior.
is unforgivable to me this type of "error" can not be present or be allowed in any type of program to boast (nothing economically by the way) be a "tool" of support for carrying out calculations. The errors committed by the spreadsheet can be so significant that could be the cause of the failure of an engineering job without thinking about the havoc that the administration would represent a small or medium business that relies on this software to "streamline" calculations.
This discovery is regrettable and generates a great deal of mistrust on this very widely used.
I have no choice but from now on to check with my financial calculator all mathematical operations that somehow compromise my work activities ... ...
