equation

问题 The following formula is used to classify points from a 2-dimensional space: f(x1,x2) = np.sign(x1^2+x2^2-.6) All points are in space X = [-1,1] x [-1,1] with a uniform probability of picking each x. Now I would like to visualize the circle that equals: 0 = x1^2+x2^2-.6 The values of x1 should be on the x-axis and values of x2 on the y-axis. It must be possible but I have difficulty transforming the equation to a plot. 回答1: You can use a contour plot, as follows (based on the examples at http

问题 We are given the following equations to help plot 'LOVE': 1/x for the 'L', (x^2)+(y^2)=9 for 'O', y=|-2x| for 'V', and -3|sin y| for 'E'. This is the code I have so far: subplot(2,2,1) x=linspace(6,15,1000); y1=1./x; plot(x,y1) subplot(2,2,2) y2=(x^2)+(y^2)==9; plot(x,y2) subplot(2,2,3) y3= abs(-2); plot(x,y3) subplot(2,2,4) y4=-3*abs(sin*y); plot(x,y4) xlabel('X') I'm having trouble plotting the 'O' graph, and also, is the rest of the code correct? 来源： https://stackoverflow.com/questions

问题 can someone help me with a document containing the theoretical exact speed of different standards of 802.11 WI-FI depending on the distance (1 to 10 meters) ? like if there is an mathematical equation that gives how the speed decrease with distance ,or software tool, or a table that gives how speed decreases every 1 meter for example , i need something very exact. THank you :) 回答1: Pure distance effect while dismissing accompanying factors is negligeble due to the following facts: Assuming

问题 I'm trying to develop an equation parser using a compiler approach in Python. The main issue that I encounter is that it is more likely that I don't have all the variables and need therefore to look for sub-formulas. Let's show an example that is worth a thousand words ;) I have four variables whom I know the values: vx, vy, vz and c: list_know_var = ['vx', 'vy', 'vz', 'c'] and I want to compute the Mach number (M) defined as equation = 'M = V / c' I already know the c variable but I don't

问题 I'm trying to develop an equation parser using a compiler approach in Python. The main issue that I encounter is that it is more likely that I don't have all the variables and need therefore to look for sub-formulas. Let's show an example that is worth a thousand words ;) I have four variables whom I know the values: vx, vy, vz and c: list_know_var = ['vx', 'vy', 'vz', 'c'] and I want to compute the Mach number (M) defined as equation = 'M = V / c' I already know the c variable but I don't

问题 In the code below, I was attempting to do a calculation if the number in the specific cell was numeric, else return number from other cell. I think that my implementation is incorrect as I only get the else state populating if the first cell is not numeric and vise versa. Can you tell me how to fix this? This is an example of the data: The 6th entry should return 27 in the Meas-LO column. Thanks Here is the code Sub ReturnMarginal() 'UpdatebySUPERtoolsforExcel2016 Dim xOut As Worksheet Dim

问题 I'm trying to get solution of cubic equations analytically in R, not numerically. I looked up on the internet and get the formula for cubic roots and wrote the following code: The link is: http://www.math.vanderbilt.edu/~schectex/courses/cubic/ cub <- function(a,b,c,d) { p <- -b/3/a q <- p^3 + (b*c-3*a*(d))/(6*a^2) r <- c/3/a x <- (q+(q^2+(r-p^2)^3)^0.5)^(1/3)+(q-(q^2+(r-p^2)^3)^0.5)^(1/3)+p x } However this function doesn't work in most cases and I guess it's because of the power of negative

问题 I know I can use Mathematica, but sadly I dont have one. I just want to find the A,B,C,D form matrix | X1^3 x1^2 X1 1 | |A| |y0| | X2^3 x2^2 X2 1 | |B| |y1| | X3^3 x3^2 X3 1 | X |C| = |y2| | X4^3 x4^2 X4 1 | |D| |y3| I just want to find the simplified equations for A, B, C and D. Actually I am trying to do a program in arduino that requires curve fitting using 4 points, so that I can predict the future points. I have seen this post , but parabola isn't accurate enough for my need. I have

问题 When I use this code to make a square root in my pdf document (rendered by rmarkdown): --- title: "Test" author: "test test" geometry: margin=1in output: pdf_document: keep_tex: yes latex_engine: xelatex number_sections: yes toc: yes toc_depth: 3 html_document: css: tables.css number_sections: yes theme: cerulean toc: yes toc_depth: 3 header-includes: - \usepackage[dutch]{babel} - \usepackage{fancyhdr} - \pagestyle{fancy} - \fancyfoot[LE,RO]{this is a fancy foot} - \usepackage{dcolumn} -

问题 I'm looking for a formula to count hours and set up a shift plan My idea is for managers, front of house and back of house to have their own planner. Where I fall at is when I try to count hours for each staff member BUT also make it legible to the reader when printed For example Staff member 4 does 0830-1600 with an hour break on Monday 1200-1900 with no break on Tuesday I want it to look like 0830-1600, but in the total hours to count out the whole week from the times put in each day 回答1: I