interp1() returns a plot with empty sections

Question

Ata about 16 hours 前

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2181964-interp1-returns-a-plot-with-empty-sections

回答： Star Strider about 16 hours 前

görsel_2025-12-24_141616445.png

I am trying to use the interp1() function to first, plot a continuous graph between a variable and time. Then I want to use the plot to look up the value of the variable at every instant. However, my plot appears to have empty sections, which is probably why I get NaN errors in my calculations. I attached my excel file also.

grade_data = readmatrix('grade.xlsx'); % reads the excel file
t_grade_raw = grade_data(:, 1)'; % Extract Time (transpose to row vector)
grade_raw   = grade_data(:, 2)'; % Extract Grade (transpose to row vector)
% Interpolating to plot
grade_interp = interp1(t_grade_raw, grade_raw, t, 'linear');
% Safety: Replace any remaining NaNs with 0
grade_interp(isnan(grade_interp)) = 0;
% Graphing
plot(t, grade_interp, 'r-', 'LineWidth', 1.5);