Columns Definition and 103 Threads

Hi, the following plots the waveforms and the FFT of a signal (one channel only): signal = data; %assuming data was loaded first Fs = 4800; % Sampling frequency T = 1/Fs; % Sampling period L = size(signal, 1); % Length of signal t = (0:L-1)*T; % Time vector X = double(signal)...

If it was about beams, I would usually do clockwise and anti-clockwise first, taking moments on A/B, clockwise forces times distance = anti-clockwise forces times distance, since its in equilibrium.

I have a number of cells (say 10 cells) but that number is a variable. I have the value of the variable but it's not a 'hard' number. We'll call the variable x. I need to calculate how many columns I'll have if the columns and rows will be the same, or the columns will be 1 minus (floor) the...

Homework Statement:: Anyone familiar with prokon column design ? I have no idea how the program caluculate the imperfection moment in the slender column (braced/unbraced... Relevant Equations:: I have attached an example here , it's an unbraced slender column here. Why the imperfection moment...

A cloumn has a compressive strength of 220MPa, but its Euler yeild stress is 350MPa. its compressive strength is less than its euler stress. what does this mean?

Hi PF! Given a matrix A = [1 2; nan 3; 3 4], how can I calculate the mean so that the resulting matrix averages the columns but ignores the nan values as non-entries, so that the mean of matrix A outputs [2,3]? Thanks so much!

$\tiny{45.4.T40}$ Suppose that the coefficient matrix of a consistent system of linear equations has two columns that are identical. Prove that the system has infinitely many solutions. Refer to the DTSLS Diagram \item using augmented matrix A for example with c1 and c3 identical $\left[...

Summary:: x Question: Book's Answer: My attempt: The coordinate vectors of the matrices w.r.t to the standard basis of ## M_2(\mathbb{R}) ## are: ## \lbrack A \rbrack = \begin{bmatrix}1\\2\\-3\\4\\0\\1 \end{bmatrix} , \lbrack B \rbrack = \begin{bmatrix}1\\3\\-4\\6\\5\\4 \end{bmatrix}...

For merging columns, I generally use the multicolumn command, while for merging rows, I use the multirow command from the multirow package. The above combination works great if there is no separator in any of the merged columns. If, however, one or more columns have separators, the code breaks...

I’ll just paste in all of the packages I’m using and the relevant code. The line in this sample that is giving me errors is line 24. (Errors below) \documentclass[10pt]{article} \pagenumbering{gobble} \usepackage[english]{babel} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb}...

How can I find maximum deflection in a column with one end fixed and other free?

I am trying to count number of rows that has values in at least 3 columns so the output based on the image shared should be 4. I tried using the code below but it is resulting in the same shape as the whole table which is 7. counts = df[(df[['a', 'b', 'c', 'd]] != 'no_label').count(axis=1) >= 3]

I have a dataframe as shown in the picture and what I am trying to do is to calculate the number of occurrences based on the values in 2 columns and then calculate the percentage of the occurrences. I have tried the following code but it gives me a zero value in the end and i don't know why...

Homework Statement Construct a 3 × 3 example of a linear system that has 9 different coefficients on the left hand side but rows 2 and 3 become zero in elimination. If the right hand sude of your system is <b1,b2,b3> (Imagine this is a column vector) then how many solutions does your system...

Say I have two columns containing data in Excel. Column A contains 10 non empty cell and column B contains 12 non empty cells. How can I create a column C with 10 + 12 cells without specifically telling Excel to put cell B1 in cell C11. In other words I would like to concatenate column A and B...

Suppose, ##A## is an idempotent matrix, i.e, ##A^2=A##. For idempotent matrix, the eigenvalues are ##1## and ##0##. Here, the eigenspace corresponding to eigenvalue ##1## is the column space, and the eigenspace corresponding to eigenvalue ##0## is the null space. But eigenspaces for distinct...

How can I find out if this matrix A's columns are linearly independent? $\begin{bmatrix}1&0\\0&0\end{bmatrix}$ I see here that $x_1 = 0$ and similarly $x_2 = 0$ does this mean that this matrix A's columns are therefore linearly dependent? Also this is a projection onto the $x_1$ axis so is it...

I am reviewing the method of partial fraction decomposition, and I get to the point that I have a matrix equation that relates the coefficients of the the original numerator to the coefficients of the numerators of the partial fractions, with the each column corresponding to a certain polynomial...

I would like to ask how to use MATLAB to append new columns into existing excel file without altering the original data in the file? In my case I don't know the original number of columns and rows in the file and it is inefficient to open the files one by one and check in practice. Another...

Suppose I have two .txt files: >>text1.txt X Y Z x1 y1 z1 x2 y2 z2 ... xN yN zN >>text2.txt W R w1 r1 w2 r2 ... wN rN Is it possible to merge the collumns in a single txt file like: >>merged.txt X Y Z W R x1 y1 z1 w1 r1 x2 y2 z2 w2 r2...

Hi guys, first time poster so play nice :) Outline of problem: The situation I have is that there are 4 supporting columns. These columns support support a wire and this wire is then used to hang wires which support festive lights. (see diagram below) What I'm looking for as an end point is...

Hi everyone.I would really appreciate if someone would help me with determination of floor load on columns (column tributary area). Normally uniformly distributed load acting on a beam is halved and each half-load is allocated to one column supporting the beam. In this case however, there is...

Hi All, Just curious as to what those with experience in creating databases believe is the best method when renaming databases: using Apex SQL , which (supposedly) automatically checks for dependencies or just sitting down , looking at the dependencies and doing the changes one by one as needed...

Hi, I was wondering if it's possible to colour the rows and columns of a matrix in mathematica. I have received help from another forum and the code of my matrix is the following: Rasterize@ Style[MatrixForm[{{n, -1 + n, -2 + n, \[CenterEllipsis], 1}, {2 n, 2 n - 1, 2 n - 2...

Homework Statement Homework Equations P=hρg The Attempt at a Solution The length of mercury column ... (1) on the left side (exposed to atmosphere) would be ( 760 + x/2 )mm (2) on the right side (exposed to atmosphere) would be ( 760 + (50-y)/2 )mm (3) on the left (exposed to air at...

Homework Statement "Fill in the empty columns of the following table" Table is in the thumbnail Homework Equations work = force / distance power = work / time Y = E * c -Y is the yearly running cost -E is the EnerGuide energy rating per year -c is the cost of electricity per kW/h The...

Homework Statement A= \begin{bmatrix} 1 & 1 & 1 & 2 & 5 \\ 2 & 3 & 1 & -1 & -5 \\ 1 & 0 & 2 & 0 & -1 \\ 1 & 2 & 0 & 1 & 2 \end{bmatrix} Homework Equations I get this RREF \begin{bmatrix} 1 & 0 & 2 & 0 & 0 \\ 0 & 1 & -1 & 0 & 0 \\ 0 & 0 & 0 & 1 & 3 \\ 0 & 0 & 0 & 0 & 0...

I feel like I almost understand the solution I've come up with, but a step in the logic is missing. I'll post the question and my solution in LaTeX form. Paraphrasing of text question below in LaTeX. Text question can be seen in its entirety via this imgur link: http://i.imgur.com/41fvDRN.jpg...

Hi! I encountered this problem that asked for the friction factor of a very dilute SO2-air gas mixture in a wetted wall column. All the necessary information were given to compute for the Reynold's number. What I want to know is does having a wetted wall make it a different case (ergo use...

I have a 3 story building. Will it be possible to put a slab (to make it a roof top) on a brick wall at 2nd floor? It was designed to construct a roof. Dimensions of brick wall: 8' X 14' Or please suggest me the best way to make a roof top on it.

This is regarding a building a house with 3 floors. I have seen some masons are first do the concrete structure and then they do the brick structure. But I have seen some do the basement first and do the bricks first and in between they keep a space for columns and they pour concrete mixture in...

When we calculate the natural frequency of an open-ended air column, is the natural frequency we calculated pertaining to the air column or the hollowed cylinder containing the air column? I imagine that the natural frequency belongs to the hollowed cylinder, for the natural frequency of...

I'm trying to learn column space currently and I'm confused about the meaning of rows and columns. So I'm given this definition for column space: "The column space of matrix A is the set Col A of all linear combinations of the columns of A" Given the matrix A: [ 1 -3 -4 ] [ -4 6 -2 ] [ -3 7...

Homework Statement Let A be an m x n matrix with m<n. Prove that the columns of A are linearly dependent. Homework Equations Its obvious that for the columns to be linearly dependent they must form a determinate that is equal to 0, or if one of the column vectors can be represented by a...

Homework Statement In a DNA molecule, the base pair adenine and thymine is held together by two hydrogen bonds (see figure below). Let's model one of these hydrogen bonds as four point charges arranged along a straight line. Using the information in the figure below, calculate the...

Homework Statement Prove that for a general NXN matrix, M, det(M)=0 => Linear Dependence of Columns Homework EquationsThe Attempt at a Solution It's not clear to me at all how to approach this. We've just started Linear algebra and this was stated without proof in lecture. I have no idea how...

See attached image. I have never heard that before. Why wouldn't one be able to implement a data structure that stores a matrix by its columns using C? Is that true?

Homework Statement [/B] This is a seemingly simple problem. All I have to do is multiply two matrices: [ 1 0 ] [ 0 1 ] (A) and [ 2 ] [ 3 ] (B) The Attempt at a Solution [/B] Because the matrix A has the same number of columns as matrix B has rows, and because matrix A is an identity matrix...

1. Imagine two columns between which is hung a string. The hung string may be expressed graphically and mathematically as a parabola whose nature is exponential. If these columns are moved closer together or farther apart, the hung string becomes more loose or taut according to a trigonometric...

Beam held up by two columns I apologize in advance if you think this should really go in the homework help area, I am not sure because this isn't a homework problem, but rather my struggle to understand and carry out concepts. If it needs to be re-posted, or moved, I understand. :) In a...

If you have an augmented matrix and one column in your matrix is all zero (but not the answer column) are you able to 'delete' the all zero column and the corresponding variable? Because when you write out the equations, the co-efficient's of the variable corresponding to the all zero column are...

Hi every body this is my first post on these forums. I have a hollow column made from structural steel that has a Young's modulus of 200GN m^-2 and a yield stress of 140MN m^-2 it is 10m long. the larger radius R is 40mm the smaller r is 30mm I am asked to find the load that will cause it to...

What mathematical algebra explains sequence of circular shifts on rows and columns of a matrix? Consider a simple matrix (3X3) with entries thus: [1 2 3; 4 5 6; 7 8 9;] Circular shifts can be performed on any row or any column thus: row-(1/2/3)-(right/left) and column-(1/2/3)-(up/dn)...

In Gilbert Strang's book on linear algebra, he mentions that pivot columns are not combinations of earlier columns and that free columns are combinations of earlier columns. What columns is he referring to by earlier columns? Also, what property distinguishes pivot variables and free...

If all columns of a matrix are unit vectors, the determinant of the matrix is less or equal 1 I am trying to prove this assertion,which i guess to be true. can anybody help me? Thank's in advance

Is the title statement true? Was doing some studying today and this caught my eye, haven't looked into linear algebra in quite a while so I'm not sure how it is true :/ Internet couldn't provide any decisive conclusions neither Many thanks

We have a distillation column with insufficient temperature tappings. In order to do a rough survey of the temperature profile externally an idea is to drill small (say 1 inch) holes in the insulation and take external temperature readings. Would a IR temp. gun like this one be a good idea...

Homework Statement Create the following matrix by typing one command. Do not type individual elements explicitly. \begin{array}{ccc} 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 1 & 4 & 7 \\ 0 & 0 & 2 & 5 & 8 \\ 0 & 0 & 3 & 6 & 9 \\ \end{array} Homework Equations None The Attempt at a...

Homework Statement Let M be the 12 x 7 coefficient matrix of a homogeneous linear system, and suppose that this system has the unique solution 0 = (0, ..., 0) \in ℝ7. 1. What is the rank of M. 2. Do the columns of M, considered as vectors in ℝ12, span ℝ12. Homework Equations The...

This is a really odd question to me. Usually we talk about b (in Ax=b) spanning the columns of A but here its talking about x spanning A. If x=<-3,4,8> (this is a vertical 3x1 matrix) is a solution to Ax=0, then is x in the set spanned by the columns of A? I'm pretty sure it is no, but i...